Biomedical subjects

M M Aruldhas

Publications and source records attributed to M M Aruldhas.

At least 19 recordsLinked to original sources

PubMed2001

Prolactin and Leydig cells: biphasic effects of prolactin on LH-, T3- and GH-induced testosterone/oestradiol secretion by Leydig cells in pubertal rats.

The effect of rat prolactin (rPRL) on basal and LH-, GH- and T3-mediated testosterone and oestradiol secretion was studied in pubertal rat Leydig cells. Purified Leydig cells were cultured for 24 h at 37 degrees C in a medium containing 4% foetal calf serum (FCS). The medium was then replaced with fresh medium containing different concentrations of rPRL (5-400 ng/mL) for 48 h at 34 degrees C without FCS. rPRL increased testosterone secretion by Leydig cells at doses of 50-400 ng and maximum stimulation was observed at a dose of 200 ng. Oestradiol secretion was parallel to that of testosterone except at low doses (5-50 ng/mL). To assess the modulatory effect of rPRL on LH-, GH- and T3-induced Leydig cell testosterone and oestradiol secretion, minimum (50 ng) and maximum (200 ng) effective doses of rPRL were co-administered with LH (25/100 ng), GH (10/50 ng) and T3 (25/50 ng). Co-administration of rPRL (50/100 ng) with T3 (25/50 ng) decreased testosterone secretion. While co-administration of T3 (25 ng) decreased rPRL-induced oestradiol secretion, the latter was unaltered at a dose of 50 ng T3. A minimum effective dose of rPRL (50 ng) plus LH (25 ng) stimulated both testosterone and oestradiol secretion. While a maximum effective dose of rPRL (200 ng) did not alter LH (25 ng)-induced testosterone and oestradiol secretion, it inhibited testosterone secretion induced by 100 ng LH and increased oestradiol secretion. Both doses of rPRL (50, 200 ng) plus GH (10/50 ng) inhibited testosterone secretion when compared with testosterone secretion induced by either GH or PRL alone and stimulated oestradiol secretion. The present in vitro study indicates that rPRL stimulates both testosterone and oestradiol secretion by Leydig cells and that this effect can be modulated by LH, GH and T3.

Animals↗

PubMed2000

Impact of oestradiol and progesterone on the glycosaminoglycans and their depolymerizing enzymes of the rat mammary gland.

The influence of oestradiol and progesterone either singly or in combination with each other on the levels of hyaluronic acid, heparan sulphate, chondroitin sulphate, and on the activity of hyaluronidase and chondroitinase were investigated in the mammary gland of ovary-intact and in ovariectomized rats, administered oestradiol and/or progesterone. Administration of oestradiol to ovary-intact rats elevated the levels of hyaluronic acid and decreased the levels of heparan sulphate while progesterone, when administered alone, could elevate only chondroitin sulphate when compared with controls. The steroids when administered in combination, however, increased the levels of all glycosaminoglycans studied. Ovariectomized animals showed a decrease in heparan sulphate alone as compared with controls while administration of oestradiol to these rats elevated the levels of both heparan sulphate and chondroitin sulphate as compared with ovariectomized rats. Also the administration of progesterone either singly or in combination increased the levels of heparan sulphate and also decreased the levels of hyaluronic acid with no impact on the levels of chondoritin sulphate. In ovary-intact animals administration of oestradiol alone had no effect on hyaluronidase activity. Progesterone either singly or in combination with oestradiol reduced the activity of hyaluronidase, whereas it had no influence on the activity of chondroitinase. The activities of both the enzymes were decreased in ovariectomized animals and administration of oestradiol and/or progesterone to the above groups resulted in an increase. This study demonstrates that oestradiol anzd progesterone play an important role in modulating glycosaminoglycans and their depolymerizing enzymes, thereby influencing the activities of the mammary epithelium.

Animals↗

PubMed2000

Thyroidectomy modulates rat prostatic monosaccharides.

Earlier studies have shown that thyroid hormones play an important role in glycoprotein metabolism in the prostate. In this paper, hypothyroidism induced changes in prostatic glycoprotein-associated monosaccharides and fructose concentrations were studied in 30-day-old peripubertal rats. Hypothyroidism was induced by total surgical thyroidectomy and confirmed by radioimmunoassay (RIA) of thyroid hormones and thyroid stimulating hormone (TSH). Animals were killed after 30 and 60 days post-thyroidectomy. To test the direct effect of thyroid hormones on prostatic monosaccharides, prostatic tissue was incubated for 24 h at 37 degrees C with 25, 50 or 100 ng/mL T3. Ventral prostatic hexosamines and sialic acid concentrations were significantly decreased in hypothyroid rats aged 30 and 60 days, whereas fucose concentration was increased at 30 days but decreased at 60 days in hypothyroid rats. In the case of the dorsolateral prostate, hypothyroidism enhanced the concentration of hexosamines but caused a decrease in levels of fucose, sialic acid and fructose, irrespective of the duration of hypothyroidism. Concentrations of fucose, fructose and hexosamines in the anterior prostate were decreased and sialic acid concentration was increased in 60-day hypothyroid rats. In in vitro studies, the concentrations of fucose, sialic acid and hexosamines were significantly increased in all three prostatic lobes irrespective of the T3 dose with which they had been incubated. A consistent increase in fructose concentration was observed in anterior and dorsolateral prostates when incubated with different doses of T3 stimulation. It is concluded that the influence of hypothyroidism on prostatic monosaccharides seems to be specific for each sugar in different lobes of the prostate. These results clearly show that thyroid hormones differentially regulate prostatic glycoprotein metabolism.

Animals↗

PubMed2000

Growth hormone directly stimulates testosterone and oestradiol secretion by rat Leydig cells in vitro and modulates the effects of LH and T3.

The modulatory effect of GH on basal, LH and T3 mediated secretion of testosterone and oestradiol by purified rat (60 day old) Leydig cells was studied in vitro. Percoll gradient purified Leydig cells (1 x 10(3)) were cultured for 48 hours at 34 degrees C in a medium containing different concentrations of rat GH (5-400 ng/mL), after an initial culture for 24 hours at 37 degrees C. GH increased testosterone and oestradiol secretions in a dose dependent manner. While testosterone secretion reached the saturation point with 50 ng GH, oestradiol secretion reached the saturation point with 150 ng GH, followed by diminished secretions. Co-administration of minimum (10 ng) effective does of GH with minimum (25 ng) or maximum (100 ng) effective doses of oLH significantly decreased the testosterone secretion. However, an increased secretion of testosterone was observed when maximum effective doses of rGH (50 ng) and oLH (100 ng) were co-administered. Minimum effective (25 ng) or maximum effective (50 ng) doses of T3 inhibited GH mediated secretion of testosterone in vitro. Oestradiol concentration in the culture medium increased when either dose of rGH was co-administered with the minimum or maximum effective doses of oLH. T3 50 ng augmented the secretion of oestradiol by Leydig cells in the presence of GH. These results indicate that GH acts as a gonadotrophin to stimulate testosterone and oestradiol secretions by Leydig cells, and that it modulates LH or T3 induced secretion of these steroids, depending on the intensity of their stimulation.

Animals↗

PubMed2000

T3 directly stimulates basal and modulates LH induced testosterone and oestradiol production by rat Leydig cells in vitro.

The effect of T3 on basal and LH mediated synthesis and secretion of testosterone and oestradiol by puberal rat Leydig cells was studied in vitro. Percoll gradient purified Leydig cells (1 x 10(3)) were cultured for 48 hours at 34 degrees C in a medium containing a range of 5-400 ng/mL concentration of T3 or ovine LH after 24 hours initial culture at 37 degrees C. T3 increased testosterone and oestradiol secretions in a dose dependent manner which reached the saturation point with 50 ng dose. While the minimum effective dose of T3 (25 ng) potentiated the stimulatory effect of the minimum effective dose of LH (25 ng) on testosterone secretion, it suppressed the effect of the saturation dose of LH (100 ng). Fifty ng T3 quelled the stimulatory effect of either dose of LH. Both doses of T3 increased oestradiol secretion, irrespective of the dose of LH. Addition of androstenedione (500 ng/mL) to the culture medium enhanced 25 ng T3 induced testosterone and oestradiol secretions. While androstenedione potentiated the stimulatory effect of T3 (25 ng) on LH (25 ng) induced testosterone and oestradiol secretions, it reversed the inhibitory effect of 50 ng T3 on LH mediated testosterone secretion which was accompanied by a decrease in oestradiol secretion. Puromycin (35 microg/mL) suppressed the stimulatory effect of T3 on basal and LH mediated testosterone and oestradiol production. Taken together, the present results indicate a direct stimulatory effects of T3 on basal production of testosterone and oestradiol by Leydig cells and its modulatory effect on LH mediated steroidogenic activity varies depending upon the intensity of LH stimuli.

Androstenedione↗

PubMed2000

Transient neonatal hypothyroidism alters plasma and testicular sex steroid concentration in puberal rats.

The stimulatory and inhibitory effects on testicular steroidogenesis of transient neonatal hypothyroidism from day 1 postpartum through different postnatal developmental events on testis at puberal age (60 days old) were studied in vivo. Hypothyroidism was induced in neonates by feeding the lactating mother or directly with 0.05% methimazole (MMI) through drinking water from the day of parturition to 10, 15, 30, 40 and 60 days, and were killed at day 60 postpartum. Plasma and testicular interstitial fluid (TIF) progesterone, testosterone, dihydrotestosterone (DHT) and estradiol concentrations were assessed. Testis weight and volume significantly increased in rats subjected to 10 and 15 days of hypothyroidism, decreased in rats subjected to 30, 40 and 60 days of hypothyroidism. A consistent increase in Leydig cell number was seen in puberal rats subjected to transient neonatal hypothyroidism but decreased in 60 days hypothyroid rats. Peritubular myoid cell number was consistently decreased in all experimental rats. Leydig cell diameter decreased consistently in all experimental groups. Persistent hypothyroidism (60 days hypothyroid) consistently decreased both plasma and TIF sex steroids. In transient hypothyroid rats, progesterone concentration decreased in both plasma and TIF. Transient hypothyroidism from birth to day 10 postnatal age maintained normal titre of plasma testosterone, whereas a significant increase in TIF testosterone concentration was evident when compared with controls. All other groups of rats subjected to transient neonatal hypothyroidism had consistently low titres of plasma and TIF testosterone. Plasma DHT concentrations in rats subjected to transient neonatal hypothyroidism remained unaltered. However, TIF DHT increased in 10 days

Animals↗

PubMed1999

Effects of piperine on testis of albino rats.

Piperine was administered to mature male albino rats at doses of 5 and 10 mg/kg body weight, p.o., respectively, for 30 days. Only a 10 mg dose of piperine treatment caused a significant reduction in the weights of testis and accessory sex organs. Histological studies revealed that piperine at a 5 mg dose caused partial degeneration of germ cell types, whereas at a 10 mg dose, it caused severe damage to the seminiferous tubule, decrease in seminiferous tubular and Leydig cell nuclear diameter and desquamation of spermatocytes and spermatids. Correlated to the structural changes, a fall in caput and cauda epididymal sperm concentrations was also evident. A 10 mg dose of piperine also caused a marked increase in serum gonadotropins and a decrease in intratesticular testosterone concentration, despite normal serum testosterone titres.

Abortifacient Agents, Steroidal↗

PubMed1999

Impact of testosterone and oestradiol on region specificity of skeletal muscle-ATP, creatine phosphokinase and myokinase in male and female Wistar rats.

The main aim of the present study was to test the hypothesis that skeletal muscle ATP concentration, creatine phosphokinase and myokinase enzyme activities are stimulated by the sex steroids in both male and female rats (animals were not subjected to any kind of exercise or any training). To test the hypothesis healthy mature (90-120 days old, weighing about 160-180 g) male and female rats were gonadectomized. Gonadectomized male and female rats were administered with testosterone (Sigma Chemical, St Louis, MO, USA) at a dose of 100 microg (100 g body weight)-1 day-1 for males and 5 microg (100 g body weight)-1 day-1 for females for 30 days from day 31 post-castration onwards; and oestradiol at a dose of 5 microg (100 g body weight)-1 day-1 for 30 days from day 31 post-castration onwards for both males and females (17beta oestradiol, Sigma Chemical Company, St Louis, MO, USA). The ATP content, creatine phosphokinase and myokinase enzyme activities of skeletal muscles were significantly higher than that of skeletal muscles of female control rats. Gonadectomy resulted in a significant decrease in ATP content and creatine phosphokinase myokinase enzyme activities in both male and female rats. Testosterone treatment to gonadectomized male rats brought back the parameters to normalcy whereas the same to the female rats enhanced the enzyme activities and ATP contents to the level of control male rats. Oestradiol treatment to castrated male rats did not bring about any significant alterations whereas the same in gonadectomized female rats brought them back to normalcy. Therefore from the present study it is concluded that testosterone is effective in both males and females whereas oestradiol was effective only in the females in enhancing skeletal muscle energy metabolism.

Adenosine Triphosphate↗

PubMed1999

Effects of ethanol ingestion on sperm monosaccharides and fertility.

Chronic alcohol abuse is often associated with reproductive disorders. Sperm monosaccharides play an indispensable role in sperm-egg interactions and fertilization. Ethanol (3 g/kg body weight as 25%, v/v) was given by gastric intubation twice daily for 30 days while in another group, rats which had been treated with ethanol were withdrawn from treatment for a further period of 30 days, in order to assess the reversibility of the ethanol-induced effects. Epididymal ethanol content, sperm monosaccharides and the fertility of ethanol treated and ethanol withdrawn rats were assessed. Ethanol ingestion caused a significant decrease in sperm monosaccharides suggesting defective glycosylation of sperm surface proteins. Sperm monosaccharides and fertility were returned to normal following the withdrawal of ethanol. Ethanol-induced changes in sperm monosaccharides may be one of the reasons for the reduced fertility of ethanol treated rats.

Animals↗

PubMed1999

Effects of piperine on the lipid composition and enzymes of the pyruvate-malate cycle in the testis of the rat in vivo.

Effects of piperine at two oral doses (5 and 10 mg/kg body weight for 30 days) on the lipid composition and some lipogenic enzymes of the rat testis were studied. Piperine treatment depleted the total lipid content which was mainly due to the diminution of the total phospholipid concentration. All the classes of phospholipids were decreased markedly following high dose piperine treatment. In contrast, a marked increase in total cholesterol and cholesterol ester was evident with a concomitant fall in free cholesterol. A similar trend was found for the total glyceride glycerol and its fractions. Total glyceride glycerol and triacyl glycerol showed a significant increase at the expense of diacyl glycerol in rats treated with the high dose of piperine. Lipogenic enzymes, malate dehydrogenase (MDH), malic enzyme (ME) and isocitrate dehydrogenase (ICDH) were inhibited by the high dose and only MDH and ME activities were inhibited by the low dose treatment.

Administration, Oral↗

PubMed1999

Differential response of rat skeletal muscle glycogen metabolism to testosterone and estradiol.

Although reports on sex steroids have implicated them as promoting protein synthesis and also providing extra strength to the skeletal muscle, it remains unclear whether sex steroids affect glycogen metabolism to provide energy for skeletal muscle functions, since glycogen metabolism is one of the pathways that provides energy for the skeletal muscle contraction and relaxation cycle. The purpose of the current study was to show that testosterone and estradiol act differentially on skeletal muscles from different regions, differentially with reference to glycogen metabolism. To study this hypothesis, healthy mature male Wistar rats (90-120 days of age, weighing about 180-200 g) were castrated (a bilateral orchidectomy was performed to test the significance of skeletal muscle glycogen metabolism in the absence of testosterone). One group of castrated rats was supplemented with testosterone (100 microg/100 g body weight, i.m., for 30 days from day 31 postcastration onwards). To test whether estradiol has any effect on male skeletal muscle glycogen metabolism 17beta-estradiol (5 microg/100 g body weight, i.m., for 30 days from day 31 postcastration onwards) was administered to orchidectomized rats. To test whether these sex steroids have any differential effect on skeletal muscles from different regions, skeletal muscles from the temporal region (temporalis), muscle of mastication (masseter), forearm muscle (triceps and biceps), thigh muscle (vastus lateralis and gracilis), and calf muscle (gastrocnemius and soleus) were considered. Castration enhanced blood glucose levels and decreased glycogen stores in skeletal muscle from head, jaw, forearm, thigh, and leg regions. This was accompanied by diminished activity of glycogen synthetase and enhanced activity of muscle phosphorylase. Following testosterone supplementation to castrated rats, a normal pattern of all these parameters was maintained. Estradiol administration to castrated rats did not bring about any significant alteration in any of the parameters. The data obtained suggest a stimulatory effect of testosterone on skeletal muscle glycogenesis and an inhibitory effect on glycogenolysis. Estradiol did not play any significant role in the skeletal muscle glycogen metabolism of male rats.

Animals↗

PubMed1998

Prostate-thyroid axis: stimulatory effects of ventral prostate secretions on thyroid function.

BACKGROUND: Endocrine cells of the prostate secrete thyrotropin (TSH)-releasing hormone (TRH), TRH- and TSH-like peptides, and growth factors. Propylthiouracil- and methimazole-induced hypothyroidism increased prostatic levels of TRH in rats as in hypothalamus, whereas thyroxine (T4) replacement decreased TRH. From these reports, we inferred the existence of a prostate-thyroid axis. METHODS: The influence of the prostate on the thyroid gland was studied in albino rats. Ventral prostate was surgically removed on day 31 postpartum. The animals were sacrificed on day 60 postoperation. Serum thyroid hormones were assayed by radioimmunoassay (RIA). For in vitro studies, normal thyroid and ventral prostate glands were cocultured with or without thyroid-stimulating hormone (TSH) antibody, to assess the direct influence of prostatic secretions on thyroid hormone secretion. RESULTS: Serum total and free T4 and triiodothyronine (T3) were significantly reduced in ventral prostatectomized rats. Histological analysis of the thyroid showed that the diameters of the peripheral and middle follicles, colloid epithelial cells, and nuclei were increased in prostatectomized rats, indicating hypothyroid status. Total T3 and T4 were significantly elevated in the culture medium when thyroid and prostate were cocultured, irrespective of the presence of TSH antibody. CONCLUSIONS: The present study suggests that ventral prostatic secretions have a stimulatory role on the thyroid gland.

Aging↗

PubMed1998

Impact of altered thyroid hormone status on prostatic glycosidases.

The impact of hyper- and hypothyroidism on prostatic glycosidases was investigated. Hyper-thyroidism was induced by administering L-thyroxine (25 micrograms/100 g body weight/day) for 60 days and hypothyroidism was induced by total thyroidectomy. To test the direct influence of thyroid hormones, prostatic lobes were incubated with different concentrations (10, 25 and 50 ng/mL) of T3 and beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase were assayed. Serum levels of thyroid hormones, oestradiol and testosterone increased in hyperthyroid, and decreased in hypothyroid rats. TSH decreased in hyperthyroid, and an opposite trend was seen in thyroidectomized, rats. Prostatic [anterior (coagulating glands), dorsolateral and ventral prostates] beta-glucosidase, beta-galactosidase, beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase activities increased uniformly in hyperthyroid, and decreased in thyroidectomized, rats. In vitro studies showed a dose-dependent stimulatory effect of T3 on beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase in all three lobes of the prostate. From the present study, it is concluded that hyperthyroidism augments and hypothyroidism inhibits prostatic glycosidases and T3 has a direct stimulatory effect on these enzymes.

Animals↗

PubMed1998

Interaction of estradiol, progesterone and corticosterone on uterine connective tissue degrading enzymes.

The impact of ovarian hormones and corticosterone acetate on uterine connective tissue degrading enzymes were studied in mature albino rats. Ovariectomy resulted in a significant increase in the activities of alpha- and beta-galactosidases and glucosidases in the uterus. Administration of estradiol to ovariectomized rats brought back the activities of alpha-galactosidase and alpha-glucosidase to normalcy. While beta-galactosidase and beta-glucosidase were significantly decreased. Administration of progesterone to ovariectomized rats resulted in the increase of alpha- and beta-galactosidases and glucosidases. Administration of corticosterone to ovariectomized rats produced a further increase in alpha- and beta-galactosidases and glucosidases in the uterus. Adrenalectomy in ovary intact rats produced a decrease in alpha-galactosidase however, beta-glucosidase was significantly increased. Administration of corticosterone to ovary intact rats significantly increased the activities of alpha- and beta-galactosidases, while alpha- and beta-glucosidases were found to be decreased. Ovariectomy resulted in a significant increase in the activities of cathepsin-D and cathepsin-E. Administration of estradiol to ovariectomized rats brought back the activity of cathepsin-D to normalcy, whereas cathepsin-E was significantly increased. Administration of progesterone as well as estradiol to ovariectomized rats significantly increased the levels of cathepsin-E, however, cathepsin-D was brought back to normalcy. Administration of corticosterone to ovariectomized rats as well as ovariectomy + adrenalectomy significantly increased the activity of cathepsin-D and cathepsin-E. Adrenalectomy significantly decreased the activity of cathepsin-D, while administration of corticosterone increased the cathepsin-D and cathepsin-E in the uterus. Therefore, these results suggest that estradiol is a potent ovarian steroid protecting the extra cellular matrix components. The effect of progesterone appears to modulate and act hand in hand with estradiol. Corticosterone appears to have an opposite effect to that of estradiol.

Adrenalectomy↗

PubMed1996

Influence of hyperthyroidism induced at prepuberty on the epididymal lipids, number and motility of spermatozoa in rats.

Fifteen prepubertal rats were divided into 3 groups of 5 each: (1) hyperthyroid group (TH), the rats were treated with thyroxine (T4) (25 micrograms/100g body weight/day) for 60 days from the age of day 31 to day 90; (2) T4-withdrawal group (TH-T4), the rats were given T4 for 30 days from the age of day 31 to day 60 and then the T4 treatment was withdrawn for the following 30 days from the age of day 61 to day 90 and the animals were given vehicle during this period; and (3) control group, the rats were given vehicle for 60 days from the age of day 31 to day 90. All were killed at the age of day 91. Serum levels of testosterone, T4 and triiodothyronine increased in the TH group (P < 0.001). The levels decreased to the euthyroid status in the TH-T4 group. Hyperthyroidism caused various changes in the levels of epididymal lipids. The levels changed further or were restored differentially in the TH-T4 group. The number of spermatozoa decreased, in caput epididymis (CpE) as well as in cauda epididymis (CdE), in the TH group (P < 0.001). The number was not restored in the TH-T4 group. The forward motility of the spermatozoa, determined in CdE, decreased in the TH group (P < 0.001) and was not restored in the TH-T4 group. The study showed that chronic hyperthyroidism, induced at the prepubertal age, causes various changes in epididymal lipid composition and sperm parameters. The study may be helpful in revealing the reasons for male infertility in hyperthyroid patients.

Animals↗

PubMed1995

Inhibition of Leydig cell activity in vivo and in vitro in hypothyroid rats.

Leydig cell steroidogenic activity under basal and stimulated conditions was studied in hypothyroid rats. Hypothyroidism was induced at a prepubertal age (30 days postpartum) by surgical thyroidectomy, and L-thyroxine (T4) supplementation (6 micrograms/100 g body weight/day for 30 days) to hypothyroid rats was begun after 30 days. Hypothyroidism for 60 days reduced serum LH and FSH without affecting prolactin. Serum and intratesticular testosterone and the specific activity of Leydig cell 3 beta- and 17 beta-hydroxysteroid dehydrogenases diminished in hypothyroid rats. The stimulatory effect of LH on Leydig cell steroidogenic activity and cAMP was also adversely affected in hypothyroid rats. All these changes were reversed by T4 supplementation. The present results suggest that prepubertal hypothyroidism suppresses both basal and stimulated Leydig cell activity in adult rats.

17-Hydroxysteroid Dehydrogenases↗

PubMed1994

Influence of hypothyroidism induced at prepuberty on epididymal lipids and the number and motility of spermatozoa in rats.

Fifteen prepubertal male rats (age 30 days) were divided into three groups of five each: Group 1, hypothyroid (Tx)--rats were thyroidectomized at day 30; Group 2, T4 (L-thyroxine) replacement therapy (Tx+T4)--rats were thyroidectomized at day 30 and treated daily i.m. with T4 (6 micrograms/100 g body weight/day) for 30 days from day 31 to day 60 post-thyroidectomy (age 90 days); Group 3, control--rats were sham-operated and treated with vehicle. The rats from all groups were killed on day 61 post-thyroidectomy or post-sham operation (age 91 days). The serum levels of testosterone, T4 and T3 decreased in the Tx group (p < 0.001). In the Tx+T4 group the levels of T4 and T3 were restored to control values, whereas testosterone levels remained lower than in the control group. Hypothyroidism caused various changes in the levels of epididymal phospholipids and neutral lipids. These were restored differentially or were altered further in the Tx+T4 group. The number and forward motility of spermatozoa, recovered from the cauda epididymis, were decreased significantly (p < 0.01) in the Tx group and were not restored in the Tx+T4 group. This study shows that chronic hypothyroidism, induced at prepuberty and continued for 60 days, causes various changes in the lipid composition of the caput and cauda epididymis and lowers the quality and quantity of spermatozoa in the cauda epididymis. T4 therapy for 30 days, especially during the postpubertal period, did not restore the quality or quantity of spermatozoa and caused differential changes in the levels of epididymal lipids, depending upon the region.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Prolactin and bromocriptine induced changes in liver, adipose tissue and blood lipids of mature male bonnet monkeys, Macaca radiata (Geoffroy).

Effects of prolactin and bromocriptine on neutral and phospholipids of liver, adipose tissue and serum were studied in mature male bonnet monkeys. Hyperprolactinemia (ovine prolactin, 250 micrograms/kg body weight/day, i.p. for 30 days) elevated hepatic total lipids and phospholipids and decreased total and free cholesterol. While triacyl glycerol accumulated, mono-and diacyl glycerols diminished in liver and adipose tissues of prolactin treated monkeys. Concentrations of all phospholipid fractions, except sphingomyelin and cardiolipin in adipose tissue accrued in both tissues. Serum triacylglycerol, phosphatidyl ethanolamine, phosphatidyl choline and phosphatidyl inositol showed a significant increase in hyperprolactinaemic monkeys. Bromocriptine (1 mg/kg body weight/day for 30 days) treatment reduced serum phospholipids without altering hepatic or adipose tissue lipids. The present study indicates that hyperprolactinaemia leads to hyperlipidemia due to accretion of hepatic and adipose tissue triacyl glycerol and certain phospholipid fractions. Bromocriptine has a specific inhibitory effect on serum phospholipids.

Adipose Tissue↗