A large body of evidence indicates that neuropeptide Y (NPY) is involved in stimulation of basal and cyclic release of hypothalamic LHRH and pituitary LH. To identify the NPY receptor subtypes that mediate the excitatory effects of NPY in these two modalities of LH release, we studied the effects of 1229U91, a selective Y1 receptor antagonist and Y4 receptor agonist, in two experimental paradig...

To determine if glucose availability modulates the timing of the positive feedback action of oestrogen on gonadotropin secretion, we monitored the estradiol-induced luteinizing hormone (LH) surge in sheep (n = 5/group) made transiently hypoglycemic by insulin. Experiment 1 determined an effective insulin treatment, one which would depress tonic LH secretion. Two injections of insulin (5 IU/kg i...

Luteinizing hormone (LH) regulates several ovarian functions. However, the luteoprotective mechanisms of LH involved in the maintenance of bovine corpus luteum (CL) function are not well understood. Since prostaglandin F2α (PGF), PGE2 and progesterone (P4) are well documented as antiapoptotic factors in the bovine CL, we hypothesized that LH protects the CL by stimulating the local production a...

A radioimmunoassay (RIA) method for luteinizing hormone (LH) releasing hormone (RH) utilizing rabbit antiserum against synthetic (Glu1)-LH-RH coupled with human serum albumin at the N-terminus, is described. This assay system for LH-RH also cross-reacted with several LH-RH analogues or fragments, but not with pituitary trophic hormones. The assay was performed on the hypothalamic extracts of ad...

Cocaine stimulates luteinizing hormone (LH) release in rhesus monkeys and in men, but its effects on LH in women are unknown. Cocaine (0.2 and 0.4 mg/kg i.v.) was administered to groups of follicular and luteal phase women (N = 22) and to men (N = 12) to examine the influence of gender and menstrual cycle phase on cocaine and LH interactions. All subjects met American Psychiatric Association Di...

Chorionic gonadotropin (CG) and lutropin (LH) are members of a family of glycoprotein hormones that share a common alpha subunit but differ in their hormone-specific beta subunits. The glycoprotein hormone beta subunits share a high degree of amino acid homology that is most evident for the LH beta and CG beta subunits having greater than 80% sequence similarity. However, transfection studies h...

Life history (LH) theory provides an evolutionary theoretical framework for understanding individual differences in maturation, mating, reproduction, parenting, and social interaction. However, the psychometric assessment of human life history has been largely limited to generalized self-reports. Using template matching, this article examines the relationship between personality differences ass...

We studied the role of lateral hypothalamus (LH) in context-induced reinstatement (renewal) of reward seeking. Rats were trained to respond for 4% (v/v) alcoholic beer or 10% (w/v) sucrose reward in one context (Context A) before extinction training in a second context (Context B). On test, rats were returned to the training context, A (ABA), or the extinction context, B (ABB). Return to the tr...

The relative r\l=o^\lesof FSH and LH in ovulation induction in immature and adult cycling rats and hamsters have been evaluated. Both heterologous purified pituitary hormones and homologous crude pituitary extracts have been used as ovulatory stimuli in immature animals primed with PMSG. Well-characterized FSH and LH antisera have been used in the above model systems to achieve specific neutral...

OBJECTIVE Independent investigations have shown that socioeconomic status (SES) and learned helplessness (LH) are associated with poor disease outcome in patients with rheumatoid arthritis (RA). Our aim was to investigate the cross-sectional relationship between SES, LH, and disease outcome in patients with recent-onset inflammatory polyarthritis (IP), the broader group of conditions of which R...