Effect of metoclopramide on luteinizing hormone secretion in postpartum anestrous cows

F. N. Thompson From the Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 (Thompson, Jones, Mizinga, Smith), and USDA-ARS Southern Piedmont Research and Conservation Laboratory, Watkinsville, GA 30677 (Stuedemann).

Search for other papers by F. N. Thompson in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
R. D. Jones From the Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 (Thompson, Jones, Mizinga, Smith), and USDA-ARS Southern Piedmont Research and Conservation Laboratory, Watkinsville, GA 30677 (Stuedemann).

Search for other papers by R. D. Jones in
Current site
Google Scholar
PubMed
Close
 DVM
,
J. A. Stuedemann From the Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 (Thompson, Jones, Mizinga, Smith), and USDA-ARS Southern Piedmont Research and Conservation Laboratory, Watkinsville, GA 30677 (Stuedemann).

Search for other papers by J. A. Stuedemann in
Current site
Google Scholar
PubMed
Close
 PhD
,
K. M. Mizinga From the Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 (Thompson, Jones, Mizinga, Smith), and USDA-ARS Southern Piedmont Research and Conservation Laboratory, Watkinsville, GA 30677 (Stuedemann).

Search for other papers by K. M. Mizinga in
Current site
Google Scholar
PubMed
Close
 PhD
, and
C. K. Smith From the Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 (Thompson, Jones, Mizinga, Smith), and USDA-ARS Southern Piedmont Research and Conservation Laboratory, Watkinsville, GA 30677 (Stuedemann).

Search for other papers by C. K. Smith in
Current site
Google Scholar
PubMed
Close
 BS

Click on author name to view affiliation information

Summary

The effect of metoclopramide (mc), a dopamine antagonist on luteinizing hormone (lh), was examined in anestrous primaparous cows. Metoclopramide has been found to be beneficial in overcoming fescue toxicosis; increasing lh secretion stimulates return to ovulatory function after parturition. Consequently, if mc had negative effect on lh secretion, it would indicate that administration of mc to reproducing animals might be limited. Of 14 postpartum (47 to 66 days) cows, 7 were given mc (4 mg/kg of body weight, iv), and 7 served as controls. Blood was obtained via jugular cannulas at 15-minute intervals for 8 hours; mc was given at the end of the first hour, and gonadotropin-releasing hormone (GnRH, 7 mg/kg), was given iv at the end of hour 7 as a challenge stimulus for lh secretion. Prior to GnRH administration, mc did not have significant effect on lh secretion, as judged by mean serum lh concentration, lh pulse frequency, and lh pulse amplitude. Administration of mc resulted in greater (P < 0.05) lh response to GnRH, indicating enhanced secretory ability when the pituitary gland was challenged. Serum prolactin concentration was increased (P < 0.01) by mc administration. Therefore, mc did not have adverse effect on lh secretion in postpartum cows.

Summary

The effect of metoclopramide (mc), a dopamine antagonist on luteinizing hormone (lh), was examined in anestrous primaparous cows. Metoclopramide has been found to be beneficial in overcoming fescue toxicosis; increasing lh secretion stimulates return to ovulatory function after parturition. Consequently, if mc had negative effect on lh secretion, it would indicate that administration of mc to reproducing animals might be limited. Of 14 postpartum (47 to 66 days) cows, 7 were given mc (4 mg/kg of body weight, iv), and 7 served as controls. Blood was obtained via jugular cannulas at 15-minute intervals for 8 hours; mc was given at the end of the first hour, and gonadotropin-releasing hormone (GnRH, 7 mg/kg), was given iv at the end of hour 7 as a challenge stimulus for lh secretion. Prior to GnRH administration, mc did not have significant effect on lh secretion, as judged by mean serum lh concentration, lh pulse frequency, and lh pulse amplitude. Administration of mc resulted in greater (P < 0.05) lh response to GnRH, indicating enhanced secretory ability when the pituitary gland was challenged. Serum prolactin concentration was increased (P < 0.01) by mc administration. Therefore, mc did not have adverse effect on lh secretion in postpartum cows.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 47 47 14
PDF Downloads 6 6 0
Advertisement