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Biomedical subjects

T Malini

Publications and source records attributed to T Malini.

17 recordsLinked to original sources
PubMed2005

Effects of streptozotocin-diabetes and insulin replacement on the epididymis of prepubertal rats: histological and histomorphometric studies.

The present study evaluates the effects of streptozotocin (STZ)-induced diabetes and insulin replacement on the histoarchitecture of caput, corpus, and caudal epididymides during the critical period of sexual maturation in rats. Prepubertal male Wistar rats (40 days old) were made diabetic by a single injection of STZ (120 mg/kg body weight, intraperitoneally). To one set of diabetic rats, insulin was replaced daily at a dose of 3 U/100g body weight, subcutaneously in two equally divided doses at 8:00 a.m. and 6:00 p.m. All the rats were killed on the 61st day of postnatal life. STZ-diabetes reduced the body weight and also caused regression of epididymis, leading to a decrease in the absolute weight of caput, corpus, and caudal regions. Histological studies also revealed a considerable reduction in the size of the tubule and lumen of these segments with an increase in interstitial stroma. Because of shrinkage of tubules, principal cells were packed tightly with clumping of nuclei. Stereological studies support atrophic changes in the caput, corpus, and caudal epididymides by reduction in tubular diameter, volume, and surface density. The epididymal lumen of STZ-treated rats was totally devoid of spermatozoa. These findings emphasize the detrimental effects of diabetes on the maintenance and establishment of fully differentiated epididymal epithelium during sexual maturation. Insulin replacement was only able to prevent the adverse effects of diabetes on certain parameters and this response was region-specific.

Animals↗
PubMed2003

The role of luteinizing hormone and prolactin in the regulation of insulin receptors in Leydig cells of the adult rat.

The role of luteinizing hormone (LH), prolactin and their combination in the regulation of insulin receptors in Leydig cells was studied. Leydig cells were isolated from adult male Wistar rats and measurement of insulin binding and internalization was done by incubating the cells with a saturating concentration of 125I-insulin in the presence or absence of different doses of unlabeled LH/insulin. LH exposure (100 and 200 ng dose) caused a significant increase in Leydig cell surface and internalized insulin receptor concentrations. Prolactin at all doses was ineffective in inducing a significant change in insulin receptor concentration. Under basal condition, Leydig cell surface binding of 125I-insulin was greater than the internalization at 34 degrees C but at 4 degrees C, surface binding remained lower than that at 34 degrees C with negligible internalization. Internalization of insulin receptors was measured by incubating the cells at 4 degrees C for 16h and then rapidly incubating at 34 degrees C for various time intervals (60, 120, and 180 min). LH/PRL or LH + PRL did not induce any significant change in the internalization of 125I-insulin at 60 and 120 min. The rate of internalization was greater at 120 min in basal as well as LH/PRL exposed Leydig cells, compared to 60 min of incubation. Prolactin alone did not evoke any appreciable change in internalization of 125I-insulin compared to basal at all three time points tested. Total and acid soluble release of 125I-insulin recorded a significant increase in Leydig cells exposed to LH, which was marginally potentiated when prolactin was added along with LH. Monensin treatment of Leydig cells prevented the recycling of insulin receptors to the cell surface and thereby suppressed the surface binding and enhanced the internalized 125I-insulin. Under cycloheximide treatment, neither surface bound nor internalized 125I-insulin recorded a significant change compared to their respective basal values. It is concluded from the present study that LH has dose-dependent biphasic effects on insulin receptors in Leydig cells by modulating the internalization and intracellular processing of hormone-receptor complexes but prolactin has no such effects.

Animals↗
PubMed2000

Studies on methotrexate effects on testicular steroidogenesis in rats.

The effects of single dose, 4 consecutive days, 4 and 8 weekly doses of methotrexate (MTX) treatment (3 mg/kg body weight, intramuscularly) with and without leucovorin (LCN) supplementation (0.3 mg/kg body weight, intramuscularly) on serum testosterone titres, total, free and esterified cholesterol concentrations and steroidogenic enzymes, viz. 3beta- and 17beta-hydroxy steroid dehydrogenase activities were studied in adult albino rats. MTX treatment caused a marked reduction in serum testosterone titres in all the treatment groups in a duration-dependent manner. LCN supplementation did not restore serum testosterone titres to normalcy. Total and free cholesterol concentrations remained unaltered in both MTX and MTX + LCN treated groups. On the other hand, a marked increase in esterified cholesterol concentration was evident only in weekly dose treatment groups. The specific activities of 3beta- and 17beta-hydroxy steroid dehydrogenase were markedly diminished in both MTX and MTX + LCN treated groups. The results suggest the inhibitory effect of MTX on steroidogenesis.

17-Hydroxysteroid Dehydrogenases↗
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

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

Effects of ethanol treatment on epididymal secretory products and sperm maturation in albino rats.

Alcoholics are often associated with fertility disturbances with low sperm count and impaired sperm motility. Spermatozoa attains forward motility and fertilizing capacity during their transit through the epididymis. Epididymal secretory products form a suitable microenvironment, which favors sperm maturation. To study the effects of ethanol on epididymal sperm maturation, ethanol (3 g/kg body weight as 25%, v/v) was given by gastric intubation twice daily for 30 days, and in another group, rats given treatment for 30 days were withdrawn of treatment for a further period of 30 days to assess the reversibility of ethanol-induced changes. Serum and epididymidal testosterone and dihydrotestosterone (DHT), epididymidal tissue and sperm carnitine, acetyl carnitine, glycerylphosphoryl choline (GPC), and sialic acid were studied along with epididymidal sperm count and cauda epididymidal sperm motility. Ethanol treatment significantly reduced the epididymal tissue/sperm carnitine, acetyl carnitine, GPC, and sialic acid, suggesting its adverse effect on these secretory products. Impaired cauda epididymidal sperm motility and fertility (in vivo) of ethanol-treated rats imply the defective sperm maturation. All these changes were reverted back to normalcy after withdrawal of ethanol treatment, indicating the transient effects of ethanol. In conclusion, it is evident that ethanol has an adverse effect on sperm maturation, which may be affected due to the decrease in serum/epididymal testosterone and DHT level and epididymal secretory products.

Acetylcarnitine↗
PubMed1998

Effects of ethanol ingestion on epididymal glycosidases and fertility in the rat.

Epididymal glycosidases play a role in sperm maturation by modifying sperm surface glycoproteins. To study the effects of ethanol on epididymal sperm maturation, ethanol (3 g/kg body weight as 25%, v/v) was administered to a group of rats by gastric-intubation twice daily for 30 days. In another group, rats were also treated with alcohol for 30 days but were then withdrawn from treatment for 30 days to assess the reversibility of ethanol-induced effects. Ethanol-induced changes in epididymal tissue and sperm glycosidases, cauda epididymal sperm motility and the fertility of rats were assessed. Ethanol treatment caused a marked decrease in the specific activities of glycosidases in both tissues and spermatozoa from epididymal segments. Cauda epididymal sperm motility and the fertility of ethanol-treated rats were significantly impaired compared to control rats fed an isocaloric diet. These changes are likely to be the consequence of direct and indirect effects of ethanol mediated through subnormal testosterone and dihydrotestosterone. Most of these changes were found to be reversible. The present study suggests that impaired activity of sperm glycosidases may be one of the factors responsible for defective sperm motility and fertilizing potential in ethanol-treated rats.

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↗
PubMed1993

Effect of beta-sitosterol on uterine biochemistry: a comparative study with estradiol and progesterone.

Administration of estradiol/progesterone to ovariectomized animals significantly increased the uterine weight, RNA, DNA and protein concentrations. Similarly, administration of beta-sitosterol alone or in combination with estradiol caused a marked increase in the above parameters and the maximum influence was evident only after median and high dose treatments. However, administration of median/high dose of beta-sitosterol along with progesterone accentuated only the RNA and protein concentrations but exerted an inhibitory effect on sitosterol-induced increment in uterine weight and DNA concentrations.

Animals↗
PubMed1992

Comparative study of the effects of beta-sitosterol, estradiol and progesterone on selected biochemical parameters of the uterus of ovariectomised rats.

A comparative study was made of the effects of beta-sitosterol, estradiol-17 beta and progesterone, individually and in combinations, on certain biochemical parameters important to carbohydrate metabolism in the uteri of adult ovariectomised rats. beta-Sitosterol (SITO), estradiol (E2) and combined treatment (SITO + E2) induced significant increases in glycogen concentration and the activities of glucose-6-phosphate dehydrogenase (G6PDH), phosphohexose isomerase (PHI) and total lactate dehydrogenase (LDH). Progesterone (P) administration however, raised only the uterine PHI and LDH activities. Co-administration of P with beta-sitosterol (P + SITO) suppressed the SITO-induced increase in glycogen concentration and G6PDH activity. On the other hand, combined treatment (P + SITO) augmented total LDH activity.

Animals↗
PubMed1991

Antifertility effects of beta-sitosterol in male albino rats.

The effects of beta-sitosterol on fertility, epididymal sperm counts and testicular and accessory reproductive organ weights were evaluated in male albino rats. The effects were studied at two dosages (0.5 and 5 mg/kg per day rat subcutaneously) for 16, 32 and 48 days. The antifertility effect of beta-sitosterol was pronounced only at the high dose level, but there was a significant decrease in testicular weight and sperm concentrations after long-term treatment with the low dose of beta-sitosterol. The weights of all accessory sex tissues except caput epididymis increased following low dose sitosterol treatment. High dose treatment reduced the sperm concentrations as well as the weights of testis and accessory sex tissues in a time-dependent manner. Withdrawal of treatment for 30 days restored only the weights of accessory sex tissues to near normal conditions.

Animals↗
PubMed1990

Rat toxicity studies with beta-sitosterol.

Chronic administration of beta-sitosterol subcutaneously to rats for 60 days was well tolerated and there was no clear cut evidence of any gross or microscopic lesions either in the liver or kidney. Liver and kidney function tests were assessed by determining the blood/serum parameters like haemoglobin, blood glucose, serum protein, serum bilirubin, serum cholesterol, serum GPT and serum GOT. All the parameters were in the normal range except serum protein and serum cholesterol. Serum cholesterol was the only variable which depleted markedly in both sexes in a dose-dependent manner suggesting intrinsic hypocholesterolemic effect of the sterol.

Alanine Transaminase↗
PubMed1989

Antifertility effect of Bambusa arundinacea shoot extracts in male rats.

An ethanolic extract of Bambusa arundinacea tender shoots (BASE) caused a reduction in fertility of male rats. After administration of 300 mg/kg per day of BASE for 7 days, the fertility index decreased to 15% for control rats and to 23% after a 7-day recovery period, respectively. The number of cohabited females being successfully inseminated was reduced especially after 4 days of treatment. Complete recovery of mating behaviour was evident 8 days after BASE withdrawal. The number of spermatozoa in the caput and cauda epididymis were decreased concomitant with a decrease in the motility of spermatozoa collected from the cauda epididymis. The weights of testes, epididymides, vas deferens and prostate were also significantly decreased. The serum profile of protein and oxaloacetic/pyruvic transaminase activity show the extract to be relatively non-toxic.

Alanine Transaminase↗
PubMed1989

Effects of bamboo buds: structural and functional changes in the epididymis of rats.

An ethanolic extract of the tender shoots of Bambusa arundinaceae was administered at 300 mg/kg per rat per day for 7 days to adult male rats to assess epididymal structural and functional activity. Sperm motility decreased markedly in the cauda epididymal fluid and sperm count decreased significantly in both caput and caudal segments of the epididymis. Histologically, a reduction in epithelial and stereocilia height (in both segments) and lumen diameter (in cauda) was noted. An increase in intertubular stroma was also evident. Epididymal weights, activities of acid phosphatase and total LDH were reduced in both epididymal segments. Protein concentration was appreciably increased only in the caudal segment. Extract therapy impaired the structural and functional integrity of the epididymis.

Acid Phosphatase↗
PubMedDate not supplied

Effect of Foeniculum vulgare Mill. seed extract on the genital organs of male and female rats.

Following the oral administration of acetone extract of Foeniculum vulgare (fennel) seeds for 15 days is male rats, total protein concentration was found to be significantly decreased in testes and vas deferens and increased in seminal vesicles and prostate gland. There was a decrease in activities of acid and alkaline phosphatase in all these regions, except that alkaline phosphatase was unchanged in vasa. In female rats, oral administration of the extract for 10 days led to vaginal cornification and oestrus cycle. While moderate doses caused increase in weight of mammary glands, higher doses increased the weight of oviduct, endometrium, myometrium, cervix and vagina also. The results confirm the oestrogenic activity of the seed extract.

Animals↗