# BRAIN-GUT PEPTIDES IN FEMALE REPRODUCTION-OVULATION

> **NIH NIH R01** · UNIVERSITY OF FLORIDA · 1994 · $184,347

## Abstract

Clinically, eating disorders (obesity, anorexia nervosa, dieting) are
associated with subnormal or impaired reproductive function. Recent
evidence shows that Neuropeptide Y (NPY), neuropeptide K (NPK) and
endogenous opioid peptides (EOP) control food intake as well as
reproduction. Although produced in the same neuronal population(s) these
neuropeptides are differentially released at specific hypothalamic sites to
modulate these two basic functions. Consequently, an understanding of the
factors that regulate neuropeptide production in the perikarya and release
from remote nerve terminals at the site(s) of action is a new challenge. In
this proposal, we plan to address these issues in the control of ovulation,
especially in the preovulatory LH surge (PLS). In the rat increased
episodic secretion of LH releasing hormone (LHRH) during the critical
period on the afternoon of proestrus causes the discharge of PLS. Although
it is well known that the neural clock (NC) entrained to the daily
photoperiod activates LHRH secretion during the critical period, the origin
and route of transmission of neural signals to LHRH neurons have not been
delineated. In this context we propose to test the hypothesis that the NC
restrains the inhibitory peptidergic circuits leading to activation of
excitatory circuits which cause LHRH hypersecretion. Therefore, our focus
will be on how the NC and inhibitory circuits, viz. EOP and NPK and the
excitatory circuit, viz. NPY and adrenergic systems, operate under the
direction of ovarian steroids. The operation of these circuits will be
examined locally in the hypothalamus by studying the inter- and
intraneuronal secretory events. In addition, the hypothesis that NPK is a
potent inhibitory system that mediates the negative feedback effects of
gonadal steroids on LH release will be tested. Interneuronal communication
will be studied by analyses of peptide release in vivo and in vitro and the
intraneuronal events will be assessed by elucidating steroidal effects on
Pre-Pro NPY mRNA and peptide levels in microdissected sites. The
connections between these circuits will be analyzed by employing
pharmacological, surgical and electrolytic lesioning approaches to
interrupt the progression of signals. Major techniques are RIA of
neuropeptides, LH and ovarian steroids, anterior pituitary dispersed cell
cultures, combined autoradiography and immunocytochemistry, neuropeptide
output analysis by push-pull cannulae in vivo and hypothalamic perfusion
and incubation in vitro. Catecholamines will be measured by HPLC and
radioenzymatic assays.

## Key facts

- **NIH application ID:** 2196618
- **Project number:** 5R01HD008634-18
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **SAM.gov UEI:** NNFQH1JAPEP3
- **Principal Investigator:** SATYA P KALRA
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $184,347
- **Award type:** 5
- **Project period:** 1979-09-01 → 1996-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2196618

## Citation

> US National Institutes of Health, RePORTER application 2196618, BRAIN-GUT PEPTIDES IN FEMALE REPRODUCTION-OVULATION (5R01HD008634-18). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2196618. Licensed CC0.

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