Biomedical subjects

M M Aruldhas

Publications and source records attributed to M M Aruldhas.

At least 55 records · Page 3Linked to original sources

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↗

PubMed1994

Post-implantation fasting does not induce pregnancy failure in newly inseminated mice.

The effect of food deprivation on the rate of pregnancy failure in newly inseminated mice was evaluated. The pre-implantation fasting for 48 h beginning on day 4 or 5 postcoitum induced a high rate of pregnancy failure in newly inseminated females. However, fasting for 48 h on day 6 had a moderate effect in inducing pregnancy failure. By contrast, females which were deprived of food on day 7 postcoitum exhibited a significant reduction in the rate of pregnancy failure. Pre-implantation fasting was highly effective in inducing pregnancy failure compared to that of post-implantation fasting. The results suggest that fasting (i.e. day 4 or 5 postcoitum)--induced depression in prolactin has resulted in failure of pregnancy and fasting at post-implantation period (i.e. day 6 or after postcoitum) has not been interfered with progesterone production by placenta.

Animals↗

PubMed1994

Dorsolateral prostatic phosphomonoesterases and adenosine triphosphatases in hypo- and hyperthyroid rats.

Specific activities of phosphomonoesterases (acid and alkaline phosphatases) and adenosine triphosphatases (Mg2+, Ca2+ and Na+/K+ dependent ATPases) of dorsolateral prostate were studied in albino rats, under altered thyroid hormone status. Thyroidectomy induced hypothyroidism and thyroxine administered hyperthyroidism (25 micrograms/100 g body wt/day for 60 days, im) showed no impact on the activity of acid phosphatase. Three fold decrease in the activity of alkaline phosphatase was observed in hyperthyroid group. Ca2+ and Mg2+ dependent ATPases were significantly decreased in hypo- and hyperthyroid status whereas Na+/K+ ATPase was decreased in hyperthyroidism and showed an opposite trend in hypothyroid group.

Adenosine Triphosphatases↗

PubMed1993

Specific activities of seminal vesicular phosphomonoesterases and Mg2+-,Ca2+- and Na+/K(+)-adenosine triphosphatases in hypo- and hyperthyroid albino rats.

Hypothyroidism (surgical thyroidectomy) inhibited the activities of acid phosphatase and Mg(2+)-ATPase in seminal vesicular tissue and fluid and that of Ca(2+)- and Na+/K(+)-ATPases in fluid alone, and T4 supplementation restored normalcy in all, except acid phosphatase. Hyperthyroidism (T4 25 micrograms/100g body weight/day for 60 days, im) enhanced the activities of alkaline phosphatase and ATPases in seminal vesicular tissue and fluid, and decreased acid phosphatase activity in tissue alone. Withdrawal of T4 treatment from hyperthyroid rats (after 30 days) augmented the activity of ATPases in tissue and impaired the same in fluid, while phosphomonoesterases remained at hyperthyroid level. The results suggest specific responses of various seminal vesicular phosphatases to altered thyroid hormone status. Modification in the specific threshold of androgen/estrogen action on different phosphatases in seminal vesicles appears to be the plausible mechanism underlying these changes in hypo- and hyperthyroid conditions.

Adenosine Triphosphatases↗

PubMed1993

Effects of prolactin and androgens on enzymes of carbohydrate metabolism in seminal vesicles of castrated mature bonnet monkeys, Macaca radiata.

Effects of prolactin(Prl), bromocriptine(Br), testosterone propionate (TP), dihydrotestosterone (DHT) and combinations of these androgens with Prl/Br on the maximum catalytic capacities of seminal vesicular enzymes involved in the glycolytic and pentose phosphate pathways in castrated mature monkeys were studied. Castration decreased the activities of all of the enzymes studied such as hexokinase(HK), 6-phosphofructokinase(PFK), glyceraldehyde-3-phosphate dehydrogenase(G3PD), pyruvate kinase(PK), glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase(6PGD) in the seminal vesicles. Prl restored the activities of all of the enzymes to their normal values except G3PD. TP/DHT maintained all the enzyme activities at the normal tissue intact level. Prl given along with androgens further enhanced the androgen action with regard to all the enzymes activities except G3PD. Br decreased all of the enzymes but Br with androgens maintained all the enzyme activities at the normal level. Castration decreased significantly serum T/DHT titres but Prl did not alter Prl levels. Prl+TP/DHT elevated Prl levels. Br alone decreased serum Prl, T and DHT titres, but Br+TP/DHT decreased only Prl, elevated T and maintained DHT levels. These results suggest that Prl has a direct as well as a synergistic action with androgens on the activities of the enzymes of glycolysis and pentose phosphate pathways in the seminal vesicles of castrated monkeys.

Androgens↗

PubMed1993

Ventral prostatic phosphomonoesterases and adenosine triphosphatases in hypo- and hyperthyroid albino rats.

Specific activities of prostatic phosphomonoesterases (acid and alkaline phosphatases) and adenosine triphosphatases (Mg2+, Ca2+ and Na+/K+ dependent ATPases) were studied in albino rats, under altered thyroid hormone status. Thyroidectomy induced hypothyroidism decreased the specific activities of acid and alkaline phosphatases, Na+/K+ and Ca2+ dependent ATPases in ventral prostate. Hyperthyroidism (25 micrograms thyroxine/100g body weight/day for 60 days, im) enhanced the activities of acid phosphatase and Na+/K+ dependent ATPase, while Ca2+ dependent ATPase decreased. The altered thyroid status had no effect on the activity of ventral prostatic Mg2+ dependent ATPase. The data obtained in the present study showed differential and specific responses of various ventral prostatic phosphatases to the hypo or hyperthyroid status. The study also shows the necessity of an optimum level of thyroid hormones to maintain the normal activities of these enzymes and their secretory function in ventral prostate.

Adenosine Triphosphatases↗

PubMed1992

Role of prolactin on epididymal glycoprotein metabolism in matured monkeys, Macaca radiata: specific activities of glycosyltransferases and glycosidases.

Impact of altered serum prolactin status on enzymes involved in glycoprotein metabolism in epididymal tissue of matured monkeys was studied. Hyperprolactinemia (ovine prolactin-250 micrograms/kg body weight/day for 30 days) significantly inhibited the specific activities of dolichylphosphate mannosyl transferase, dolichylphosphate glucosyl transferase and galactosyl transferase, in the epididymal tissues. However, it had an enhanced effect on epididymal glycosidases such as beta-galactosidase, beta-N-acetyl glucosaminidase, beta-N-acetyl galactosaminidase, alpha-mannosidase and alpha-L-fucosidase. Hypoprolactinemia (bromocriptine mesylate-1-mg/kg body weight/day for 30 days) on other hand had no significant effect on the specific activities of both, glycosyltransferases and glycosidases, in the epididymal tissues. The results suggest that hyperprolactinemia inhibits epididymal glycoprotein metabolism by impairing the incorporation of oligosaccharide units into proteins with enhanced degradation. This may have adverse effect on events leading to sperm maturation in epididymal environment.

Animals↗

PubMed1992

Effects of prolactin and androgens on enzymes of carbohydrate metabolism in prostate of castrated bonnet monkeys Macaca radiata (Geoffroy).

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combinations of these androgens with PRL/Br on the specific activities of caudal and cranial prostatic cellular enzymes involved in carbohydrate metabolism in castrated mature bonnet monkeys have been studied. Castration decreased all the enzymes studied such as hexokinase (HK), 6-phosphofructokinase (6-PFK), glyceraldehyde-3-phosphate dehydrogenase (G-3-PD), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phosphogluconate dehydrogenase (6-PGD) in the cranial and caudal prostates. PRL elevated the activities of all the enzymes above normal except G-3-PD of cranial lobe. In the caudal lobe, PRL brought back the activities of HK, PFK, PK, G-6-PD to normal and 6-PGD above normal except G-3-PD. TP/DHT treatment increased all the enzymes in both the lobes. PRL given along with TP/DHT further enhanced the androgen action with regard to HK, PK, G-6-PD and 6-PGD of cranial and PFK, G-3-PD, PK, G-6-PD and 6-PGD of caudal lobe. Br treatment did not produce any alteration of these enzymes in both the lobes. In the cranial lobe, during Br+TP/DHT treatment, the stimulating effects of androgen were unaffected on all the enzymes except PK. On the other hand in the caudal, the stimulatory effects of androgens were affected and the activities of HK, PFK, PK and 6-PGD were significantly decreased. The present results suggest that PRL has a direct as well as a synergistic action with androgens on enzymes of EMP and HMP shunt in the prostates of monkeys.

Androgens↗

PubMed1992

Interaction of androgens and prolactin on prostatic enzymes of the pyruvate-malate cycle involved in lipogenesis in castrated mature monkey, Macaca radiata.

Effects of androgens, prolactin (Prl) and bromocriptine (Br) on the specific activities of prostatic (caudal and cranial) enzymes of the pyruvate-malate cycle were studied in castrated mature bonnet monkeys. Castration decreased the activity of NADP+ isocitrate dehydrogenase (ICDH), ATP citrate lyase, malate dehydrogenase (MDH), malic enzyme and fatty acid synthase (FAS). Administration of testosterone propionate (TP)/dihydrotestosterone (DHT) increased the activities of all these enzymes in both lobes. Malate dehydrogenase maintained normal activity. Prl also had a stimulatory effect on the enzymes and was further enhanced when Prl was given in combination with TP/DHT. Unlike Prl, bromocriptine treatment inhibited all the enzymes in both lobes. Thus, prolactin was found to have a direct as well as a synergistic effect with androgens on enzymes of the pyruvate-malate cycle in the prostate of castrated mature monkeys.

ATP Citrate (pro-S)-Lyase↗

PubMed1991

Influence of prolactin on pulmonary lipids in mature male bonnet monkey, Macaca radiata.

Administration of ovine prolactin (250 micrograms/kg body weight/day) for 30 days to mature male bonnet monkeys increased the pulmonary total lipids and total phospholipids. While total cholesterol did not show any appreciable change in PRL treated monkeys, the ratio of free: esterified cholesterols was altered with perceptible decrease in free cholesterol and increase in esterified cholesterol. Pulmonary tissue total glyceride glycerol concentration was diminished as a result of decreased monoacyl, diacyl and triacyl glycerols. Among phospholipid fractions, phosphatidylcholine and phosphatidylinositol were elevated while phosphatidic acid and cardiolipin were reduced. The data suggest that hyperprolactinemia interferes with pulmonary lipid metabolism in adult monkeys and modifies the ratio of cholesterol and phospholipid composition. Further, hyperprolactinemia appears to favour esterification of cholesterol with specific changes in phospholipid fractions. Thus, the present study demonstrates that hyperprolactinemia modifies the pattern of pulmonary neutral and phospholipid fractions and thereby is likely to affect the structure and function of mature primate lungs.

Animals↗

PubMed1991

Influence of thyroidectomy on seminal vesicular glycosidases of young albino rats.

Impact of thyroidectomy (hypothyroidism) on few glycosidases was studied in the seminal vesicles of young albino rats. Thyroidectomy was performed at 30 days post partum. Seminal vesicular beta-D-glucosidase, beta-D-galactosidase, and N-acetyl-beta-D-galactosaminidase exhibited a similar response of decreased activities under short- (30 days) and long-term (60 days) hypothyroid conditions. On the other hand, N-acetyl-beta-D-glucosaminidase registered a temporal biphasic response of increased and decreased activities in the seminal vesicles of rats subjected to short- and long-term hypothyroidism, respectively. The data obtained in the present study suggest that thyroid hormones have specific influences on different glycosidases in the seminal vesicles of rats and euthyroid status is essential for the maintenance of normal activities of these enzymes.

Animals↗

PubMed1990

Effects of prolactin and androgens on the prostatic lipids of castrated mature bonnet monkeys.

The effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT), and the combinations of these androgens with PRL/Br on total lipid, total cholesterol, total glyceride glycerols, and total phospholipid and their fractions in cranial and caudal prostates of castrated mature monkeys were studied. Glyceride glycerols formed the major portion of total lipids (50%) in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed the major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes in both the lobes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols in both the lobes. Phosphatidyl inositol, choline, and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal in both the lobes. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine, and phosphatidic acid in both the lobes. Br counteracted the effects of androgens and prolactin. In general, the influence of prolactin was more in the caudal lobe than cranial. The results are discussed in detail with available literature.

Animals↗

PubMed1990

Impact of hyperprolactinaemia on testicular neutral lipids and phospholipids in mature bonnet monkeys, Macaca radiata (Geoffroy).

Impact of hyperprolactinaemia, induced by daily injection of ovine prolactin (250 micrograms/kg body weight, ip for 30 days) on testicular lipids was studied in M. radiata. Wet weights of testis and accessory sex organs decreased in hyperprolactinaemic monkeys. Even though total lipids in the testis did not show any significant change, total cholesterol and total glyceride glycerol decreased. While all fractions of testicular neutral lipids showed a perceptible decrease, phosphatidic acid, phosphatidyl ethanolamine and phosphatidyl choline increased in hyperprolactinaemic monkeys. Hyperprolactinaemia appears to influence male fertility by altering the composition of testicular neutral lipids and phospholipids.

Animals↗

PubMed1989

Influence of prolactin on neural and glial cellular adenosine triphosphatases in immature male bonnet monkeys (Macaca radiata, Geoffroy).

The effect of prolactin on specific activities of adenosine triphosphatases (ATPases) in neural and gliar cells of cerebral cortex, cerebellum and pons-medulla of immature male bonnet monkeys was studied. Na+, K+ dependent ATPase was stimulated, while Mg2+ and Ca2+ dependent ATPase activities showed reduction in neural as well as glial cells of cerebral cortex and cerebellum. However, in pons-medulla, Na+, K+ and Mg2+ dependent ATPases showed the same trend in neural and glial cells, respectively, as in the other two regions. The data obtained reveal that prolactin has specific effect on different ATPases, in different regions of the brain.

Adenosine Triphosphatases↗

PubMed1989

Effect of corticosterone on epididymal lipids in pubertal rat.

Serum corticosterone excess was induced by the administration of corticosterone acetate to adrenal intact rats. Different lipid classes were studied in unwashed and washed (epididymal sperm and fluid free) caput and cauda epididymides. The unwashed caput epididymidis registered a significant decrease in total lipid, cholesterol and phospholipid while total glyceride glycerol and its fractions were not altered after corticosterone treatment. Among phospholipid fractions phosphatidyl inositol, choline and ethanolamine showed a significant decrease. Unlike the unwashed caput epididymidis, the washed caput region recorded a marked increase in total lipid, glyceride glycerol and its fractions. However, total lipid in the washed cauda region significantly increased and the increase was mainly due to triacyl glycerol. Though the phospholipid fractions phosphatidyl choline and ethanolamine showed an increase, the total phospholipid was not altered significantly. Serum testosterone and prolactin registered a significant decrease while gonadotropins were unaltered. On the withdrawal of corticosterone treatment, all the lipid classes turned to normalcy along with serum testosterone and prolactin. It is concluded that corticosterone excess favours lipid accumulation in the sperm free epididymal tissue and its influence on epididymis is region specific and reversible.

Animals↗

PubMed1989

Effects of prolactin and androgens on seminal vesicular lipids of castrated mature bonnet monkeys Macaca radiata.

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combination of these androgens with PRL/Br on the total lipid, total cholesterol, total glyceride glycerols, total phospholipid and their fractions in seminal vesicles of castrated mature monkeys were studied. Glyceride glycerols formed the major portion (50%) of total lipids in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols. Phosphatidyl inositol, choline and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine and phosphatidic acid. In all these aspects, Br counteracted the effects of androgens and PRL.

Animals↗

PubMed1988

Role of prolactin on neural and glial cellular enzymes involved in carbohydrate metabolism. I. Studies on immature male bonnet monkeys.

The influence of prolactin (Prl) and bromocriptine on the specific activities of neural and glial cellular enzymes involved in carbohydrate metabolism in cerebral cortex, hypothalamus, cerebellum and pons-medulla was studied. Both Prl and bromocriptine stimulated the activity of hexokinase (HK) in the neural as well as in the glial cells. While Prl increased the activity of phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (G-3-PDH) and pyruvate kinase (PK) in the neural cells, it decreased the same in the glial cells. On the other hand, bromocriptine elevated the activity of all these enzymes in the neural cells without any effect on the glial cells. The activities of neural cellular glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) were inhibited by Prl, whereas bromocriptine increased the same. The activities of these enzymes in the glial cells were enhanced by both Prl and bromocriptine. Thus, the present study suggests that Prl has a differential effect on the activities of enzymes involved in Embden-Meyerhoff pathway (EMP) and hexosemonophosphate shunt (HMP) in the neural and glial cells of immature male bonnet monkeys.

Animals↗

PubMed1988

Effects of androgens, prolactin and bromocriptine on seminal vesicular enzymes of the pyruvate malate cycle involved in lipogenesis in castrated mature monkeys, Macaca radiata.

The interaction of androgens and prolactin, the major factors regulating the male accessory sex organs, on the specific activity of seminal vesicular enzymes of the pyruvate/malate cycle were studied in castrated mature monkeys. Castration decreased the activity of these enzymes, including NADP+ isocitrate dehydrogenase, ATP citrate lyase, malate dehydrogenase, malic enzyme and fatty acid synthase. Testosterone propionate (TP)/dihydrotestosterone given as replacement to castrates increased the activity of all these enzymes, except for malate dehydrogenase. Prolactin restored normal activity of ATP citrate lyase, malic enzyme and fatty acid synthase but not of isocitrate dehydrogenase and malate dehydrogenase (MDH). Prolactin had a specific control over MDH. Moreover, when prolactin was combined with androgens a further stimulatory influence was observed on fatty acid synthase activity. In order to prove the direct influence of prolactin on enzymes of the pyruvate/malate cycle, bromocriptine was administered and this inhibited all of the enzymes. Thus prolactin was found to have a direct, as well as a synergistic, action with androgens on enzymes of the pyruvate/malate cycle in the seminal vesicles of monkeys.

ATP Citrate (pro-S)-Lyase↗