Opioid control of growth hormone in the suckled sow is primarily mediated through growth hormone releasing factor.

نویسندگان

  • J D Armstrong
  • K L Esbenshade
  • M T Coffey
  • E Heimer
  • R Campbell
  • T Mowles
  • A Felix
چکیده

Endogenous opioid peptides mediate the effect of suckling on LH and PRL in the domestic pig. However, the role of opioids in modulating GH during lactation in swine is not known. Primiparous sows that had been immunized against GRF(1-29) conjugated to human serum albumin (GRF-HSA, n = 5) or HSA (n = 4) were used to determine changes in GH after naloxone. Treatments were imposed in all sows on day 21 of lactation when antibody titers were 9100 +/- 1629. All sows received (i.v.) naloxone (0.25 mg/kg) or saline (0.0125 ml/kg) at 15 min intervals for 165 min. Active immunization against GRF-HSA during lactation decreased (P less than 0.05) mean concentration (4.8 +/- 0.2 vs 2.6 +/- 0.1 ng/ml) and frequency (1.5 +/- 0.3 vs 0.4 +/- 0.2 peaks/4 hr). Concentrations of LH and PRL were similar in GRF-HSA and HSA immunized sows. Naloxone suppressed (P less than 0.05) GH in all sows. In HSA sows, naloxone abolished episodic release of GH and decreased average, but not basal, concentrations of GH. In sows immunized against GRF-HSA, naloxone decreased (P less than 0.05) average and basal GH but failed to decrease frequency of GH release. Naloxone failed to alter frequency of LH release. Concentrations of PRL decreased (P less than 0.05) after naloxone in all sows. In conclusion, immunization against GRF-HSA blocked most of the effect of lactation on GH. Blocking opioid receptors with naloxone decreased GH and PRL in all sows. In contrast to previous findings naloxone had no effect on LH. Opioids alter concentrations of GH through a GRF dependent and GRF independent pathway.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Comparison of Expression of Growth Hormone-Releasing Hormone and Its Receptor Splice Variant 1 in Different Stages of Endometriosis

متن کامل

The effects of short-term growth hormone (somatotropin) bath on some growth and immunity indices in the early stages of growth in rainbow trout (Oncorhynchus mykiss)

This study was conducted to determine the effect of growth hormone on some growth and immunity parameters at three stages of rainbow trout eyed egg, alvin and fry. The experiment was carried out in 4 treatments with concentrations of 0, 0.1, 0.5 and 1 mg/l of somatotropin hormone. For permeability, different experimental groups were treated with sodium hypochlorite (0.005 %) for 15 seconds befo...

متن کامل

بررسی چند شکلی ژنتیکی و فراوانی آللی جایگاه ژنی GHRH (Growth-hormone-releasing hormone) در گاوهای سرابی ایران

   انتخاب حیوان بر اساس نشانگرهای مولکولی یکی از جدیدترین روش­های اصلاحی است که می‌تواند باعث بهبود صحت پیش‌بینی و پاسخ به انتخاب شود. GHRH (Growth-hormone-releasing hormone) یکیازژن­هایبرگزیدهبرایاستراتژی‌هایانتخاببراساسمارکرمی‌باشد.براساسگزارشاتموجود، چندشکلی‌هایژن بهطورمعنی‌داریباصفاتاجزایشیروتولیدآنارتباطدارد. به منظور بررسی چندشکلی (پلی‌مورفیسم) مکان ژنی GHRH در نژاد سرابی، از 112 رأس گاو ...

متن کامل

RT-PCR MEDIATED CLONING OF HUMAN GROWTH HORMONE GENE AND I TS EXPRESSION IN E. coli

Human growth hormone (hGH) genomic sequence containing 5 exons and 4 introns was cloned in pcDNA-3 and the constructed plasmid was subsequently used for transfection ofNlli-3T3 cell line using lipofection technique. Expression of hGH in stably transfected cells was assayed using ELISA. Total RNA was extracted from transfected cells and hGH cDNA was amplified by RT-PCR using specific primers...

متن کامل

P-24: Opioid and Progesterone Signaling Is Obligatoryfor Early Human Embryogenesis

Background: The growth factors that drive the division and differentiation of stem cells during early human embryogenesis are unknown. The secretion of endorphins, progesterone (P(4)), human chorionic gonadotropin, 17beta-estradiol, and gonadotropin-releasing hormone by trophoblasts that lie adjacent to the embryoblast in the blastocyst suggests that these pregnancy-associated factors may direc...

متن کامل

ذخیره در منابع من

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Domestic animal endocrinology

دوره 7 2  شماره 

صفحات  -

تاریخ انتشار 1990