Molecular genetic and biochemical evaluation of ghrelin hormone as a novel signal of gonadal function in adult male rats

It is well known that reproductive function is regulated by the interplay of the hypothalamus, pituitary and gonads, which form the so called reproductive axis. A number of factors primarily involved in the control of energy balance and metabolism have been proven as putative modulators of the gonadal axis, thus providing the basis for the link between energy homeostasis and fertility. Ghrelin is a 28 amino acid peptide. It is predominantly produced by the endocrine X/ A- like cells of the stomach submucosa and mobilized by food deprivation. Ghrelin concentrations were observed to change with fasting and refeeding in mammals. The potential reproductive role of ghrelin has received attention recently. The Objective of this work is to study the effect of chronic food restriction on ghrelin level in adult male rats and it's relation to reproductive hormones. The present study was carried out on 32 adult male Sprague Dawley rats divided into 4 groups: Group I [control group] comprised 8 rats fed ad libitum for 30 days, Group II, III and IV [food-restricted groups for 10, 20 and 30 days respectively] each consisted of 8 rats fed 50% of ad libitum intake determined by the amount of food consumed by the control group. Mean body weight of food restricted rats was observed to decrease during the period of the experiment. Food restriction produced significant increase of serum ghrelin with significant decrease of both gastric and hypothalamic ghrelin accompanied with significant increase in its gene expression in stomach and hypothalamus. Testosterone, follicle- stimulating hormone [FSH] and luteinizing hormone [LH] levels showed significant decrease correlated with down- regulation of gonadotropins, aromatase and kisspeptin [Kissl] genes in food restricted rats compared with control group. Ghrelin could be one of the hormones responsible for the suppression of male reproductive axis in case of negative energy balance. Thus, ghrelin could provide a link between energy homeostasis and reproductive capacity in adult male rats

Efficacy of certain amino acids in intervention of osteoporosis in ovariectomized rats

The aim of the current study was to evaluate the therapeutic role of some amino acids in the management of osteoporosis in ovariectomized [OVX] rats. This study was conducted on 56 adult female rats which were divided into 7 groups as follows: Gp.[1] OVX rats orally administered with [1 ml/rat/day] saline as vehicle; Gp.[2] OVX rats orally administered with L-lysine [1.26g/kg/b.wt.]; Gp.[3] OVX rats orally administered with L-arginine [500mg/kglb.wt.]; Gp.[4] OVX rats orally administered with L-glutamine [3.2g/kg/b.wt.]; Gp.[5] OVX rats orally administered with taurine [50mg/kglb.wt.] and Gp.[6] OVX rats orally administered with a combination of the four amino acids dissolved in saline. In addition, gonad-intact [control group] orally administered with 1 ml saline/rat/day was involved in the present study. The treatment was started after 3 months of ovariectomy and continued for other 3 months. Serum calcium [Ca], phosphours [P], parathyroid hormone [PTH], osteocalcin [OC], insuline like growth factor-1 [IGF-1], transforming growth factor-beta [TGF-beta] levels and bone alkaline phosphatase [BAP] activity were determined. Significant decrease in serum Ca, P levels and bone ALP activity as well as in serum OC, IGF-1 and TGF-beta levels were ovariectomy-induced, while it caused significant increase in serum PTH level when compared to their corresponding values in gonad-intact control rats. Treatment of OVX rats with L-lysine or L-arginine produced non-significant increase in serum Ca and P levels and the treatment with L-glutamine or taurine induced significant increase in serum Ca and P levels. Treatment with either one of the selected amino acids resulted in significant decrease in serum PTH level while these amino acids produced significant increase in serum osteocalcin level and BAP activity. Treatment of OVX rats with L-lysine induced non-significant increase in serum IGF-1 and TGF-beta, while the combination of L-arginine with either L-glutamine or taurine produced significant increase in serum IGF-1 and TGF-beta. Treatment of OVX rats with a combination of the selected amino acids resulted in significant increase in the all studied biochemical parameters except serum PTH level which showed significant decrease as compared to their corresponding values in OVX rats. Each of the selected amino acids or their combination significantly modulates markers of bone turnover in OVX rats. These results indicated the usefulness of these amino acids in the treatment of primary osteoporosis

Protective role of balanites aegyptiaca fruit extract against aflatoxin-induced inhibition of some hormones in adult rats

The protective action of Balanites aegyptiaca fruit extract against the inhibitory effect of aflatoxin, especially that produced by Aspergillus parasiticus, on the serum levels of progesterone and prolactin in female lactating rats and testosterone in adult male rats was assessed. Two groups of female lactating rats [120-160 g B.W.] and adult male rats [120-150 g B.W.] were intraperitoneally injected with a single dose of 3 mg/kg B.W. of aflatoxin. Similarly other two groups of rats were intraperitoneally injected with a single dose of 3 mg/kg B.W. of aflatoxin followed by treatment, on the next day, with oral administration of 3 mg/kg B.W. Balanites aegyptiaca fruit monocarp extract daily for a period of 30 days [post-treatment]. Serum progesterone and prolactin levels in female lactating rats and testosterone in adult male rats measured on the 16th and 31st day after injection of aflatoxin showed significant decrease [p<0.001] as compared to the normal control group. Insignificant increase [p>0.05] in serum progesterone, prolactin and testosterone levels was detected in post-treated group after 15 or 30 days of treatment with Balanites aegyptiaca fruit mesocarp extract as compared to aflatoxin-treated group. Other two groups of rats were pretreated with oral administration of Balanites aegyptiaca fruit mesocarp extract with a dose of 3 mg/kg B.W, daily for a period of 15 days followed by a single dose of 3 mg/kg B.W. of aflatoxin while continuing treatment with oral administration of Balanites aegyptiaca fruit mesocarp extract daily for other 15 days [prophylactic-treatment]. The serum progesterone and prolactin levels in female lactating rats and testosterone in adult male rats, measured at the 16th day and at 31st day showed significant increase at p<0.01 and p<0.001 respectively as compared to aflatoxin-treated group