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Effects of Lepidium sativum supplementation on growth and gonadotropins secretion in ovariectomized, estrogen-implanted rabbits
Authors: Oluwatosin V. Imade, Wuraola A. Erinfolami, Rasheed A. Ajadi, Monsuru O. Abioja, Samson A. Rahman, Olusiji F. Smith, Oladele S. Gazal
Number of views: 431
Objective: To test the effects of dietary supplementation of Lepidium sativum (LS) seed
powder on growth performance and gonadotropins secretion in ovariectomized, estradiol-
implanted rabbits. Methods: Ovariectomized, estradiol-implanted Chinchilla rabbits were
assigned into four experimental groups: LS seed powder was included into normal rabbit
chow at 0% (control), 5% (low), 7% (mid) and 10% (high) w/w. Experimental feed and
water were given ad-libitum for 3 weeks. Weekly body weights and daily feed intake of rabbits
were recorded. Twenty-one days post-feeding, blood samples were collected at 15-minute
interval for 3 h (Period Ⅰ) after which 2.5 μg gonadotropin-releasing hormone (GnRH) was
injected intravenously and the sampling continued for another hour (Period Ⅱ). Plasma was
harvested and analyzed for luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
by radioimmunoassay. Results: Feed intake was significantly (P<0.05) increased in LS-
supplemented rabbits. However, the increase in feed intake did not result in significant body
weight gain. LS seed supplementation significantly (P<0.001) increased mean plasma LH
dose-dependently from the low- to the mid-LS level and then decreased LH at the high-LS
level. LS supplementation increased (P<0.001) plasma FSH secretion. Injection of GnRH
had no effect on plasma LH, however significantly (P<0.05) decreased overall plasma FSH
secretion. Conclusions: LS seed supplementation stimulates feed intake and gonadotropins
secretion in rabbits. Gonadotropins effect may be mediated through LS seeds phytosterols
through the activation of estrogen receptors thereby producing agonistic effects resulting
in LH and FSH secretion. The differential responses of gonadotropins to GnRH in LS-
supplemented rabbits suggest differential regulation of the synthesis and secretion of these
gonadotropins.