Delayed Puberty in Spontaneously Hypertensive Rats Involves a Primary Ovarian Failure Independent of the Hypothalamic KiSS-1/GPR54/GnRH System

Spontaneously hypertensive (SH) rats, extensively used as experimental models of essential human hypertension, display important alterations in the neuroendocrine reproductive axis, which manifest as markedly delayed puberty onset in females but whose basis remains largely unknown. We analyze herein in female SH rats: 1) possible alterations in the expression and function of KiSS-1/GPR54 and GnRH/GnRH-receptor systems, 2) the integrity of feedback mechanisms governing the hypothalamic-pituitary-ovarian axis, and 3) the control of ovarian function by gonadotropins. Our data demonstrate that, despite overtly delayed puberty, no significant decrease in hypothalamic KiSS-1, GPR54, or GnRH mRNA levels was detected in this strain. Likewise, in vivo gonadotropin responses to ovariectomy and systemic kisspeptin-10 or GnRH administration, as well as in vitro gonadotropin responses to GnRH, were fully preserved in SH rats. Moreover, circulating LH levels were grossly conserved during prepubertal maturation, whereas...