James M. Hammond

Pennsylvania State University

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Johannes D. Veldhuis

Mayo Clinic in Florida

S. F. Canning

Pennsylvania State University

R. W. Grimes

Pennsylvania State University

Susan Samaras

UCLouvain

Judith S. Mondschein

Penn State Milton S. Hershey Medical Center

L. J. Spicer

Oklahoma State University

D. R. Hagen

St. Josef Krankenhaus

J. A. Barber

Pennsylvania State University

PATRICIA A. KLASE

University of Virginia

H. D. Guthrie

Agricultural Research Service

Cooperative Institutions

Pennsylvania State University

Penn State Milton S. Hershey Medical Center

University of Michigan–Ann Arbor

National Institutes of Health

Eunice Kennedy Shriver National Institute of Child Health and Human Development

Hershey (United States)

University of Pennsylvania

Harvard University

Beltsville Agricultural Research Center

United States Department of Agriculture

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The Role of Insulin-Like Growth Factors in Granulosa Cell Steroidogenesis: Studies with a Neutralizing Antibody to IGF-I

Springer eBooks (1989)

Judith S. Mondschein S. F. Canning James M. Hammond

Follicular fluid

Granulosa cell

10.1007/978-1-4684-5688-2_15

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Citations (0)

Heterogeneity of insulin receptors on fat cell membranes

Biochemical and Biophysical Research Communications (1972)

James M. Hammond Leonard Jarett Ida K. Mariz William H. Daughaday

Proinsulin

Insulin receptor substrate

Cell membrane

10.1016/0006-291x(72)90329-4

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Citations (74)

Ovarian IGF System: Interface with the Gonadotropic and Somatotrophic Axes

Springer eBooks (1995)

James M. Hammond Susan Samaras R. W. Grimes D. R. Hagen David Guthrie

Ovarian Reserve

10.1007/978-1-4612-2518-8_15

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Citations (5)

Demonstration of Specific Binding of Prolactin by Porcine Corpora Lutea

Endocrinology (1976)

R. Rolland Glen L. Gunsalus James M. Hammond

Subcellular fractions from porcine corpora lutea of the reproductive cycle and pregnancy were shown to have specific binding sites for ovine prolactin (oPRL). Aside from oPRL, only ovine and bovine growth hormone preparations competed with [125I]iodo-oPRL for its binding site. These cross reactions were at a level consistent with the prolactin contamination of these preparations. Rat growth hormone, FSH, LH, TSH, insulin, and ACTH exhibited negligible cross-reactivity. Both corpora hemorrhagica and albicantia had lower specific binding of [125I]iodoPRL than did active corpora lutea of the reproductive cycle, while corpora lutea of pregnancy demonstrated a nearly 5-fold increase in specific binding compared with that of the cycle. Corpora lutea from animals with larger fetuses (greater gestational age) bound the most prolactin. Analysis of data from cold competition studies employing weighted non-linear least-square fitting to a three-parameter model, showed high-affinity binding of oPRL with an association constant (Ka3 23 C) of 2.0 × 109M−1 for the binding site of the corpus luteum of the cycle. The Ka shows no appreciable change with pregnancy. In contrast, the binding site concentration (N) increases markedly from less than 10 fmol/mg protein in corpora lutea from non-pregnant animals to approximately 40 fmol/mg protein for animals at a gestational stage of 40–46 days. The observed Ka's are similar to values obtained for the prolactin binding site in porcine granulosa cells harvested from unruptured follicles and to the prolactin-binding site in the mammary gland. (Endocrinology98: 1083, 1976)

10.1210/endo-98-5-1083

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Citations (70)

OESTROGEN TREATMENT OF CATTLE: INDUCED LACTATION AND OTHER EFFECTS

Journal of Endocrinology (1944)

James M. Hammond F. T. Day

INTRODUCTION Normal onset of lactation In the majority of species investigated it would appear that oestrogen stimulates mammary duct growth, but that alveolar development requires luteal secretion. To this the cow and the goat are evidently exceptions, and perhaps this is not unconnected with the fact that they have been domesticated for milk production. A marked difference between the cow and the goat, which is perhaps rather singular, concerns the development of the mammary gland. Among goats of high milking strains, though not with the poorer class of animal, it is the rule rather than the exception that they may develop an udder and come into milk without ever having been mated. The onset of such a lactation comes commonly in the spring, which is also the end of the breeding season, and the yield, though less than what would be given after kidding, may yet be as great as

Udder

Milking

Milk secretion

10.1677/joe.0.0040053

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Citations (35)

Expression of the mRNAs for the insulin-like growth factors and their binding proteins during development of porcine ovarian follicles.

Endocrinology (1993)

Susan Samaras H. D. Guthrie J. A. Barber James M. Hammond

We examined the expression of the mRNAs for the insulin-like growth factors (IGFs) and two of their binding proteins (BPs), IGFBP-2 and IGFBP-3, in individual follicles of the porcine ovary. Follicular development was synchronized with a progestin (altrenogest). Individual follicles were isolated on days 1, 3, 5 and 7 after progestin withdrawal. No IGFBP-3 mRNA was detected. While IGF-II mRNA was easily detected, the levels of expression did not change. IGF-I and IGFBP-2 mRNAs increased and decreased, respectively, with follicle development until day 7 when IGF-I expression declined. Regression analysis of IGF-I and IGFBP-2 mRNA expression was performed to assess the relative strength of correlations with day, diameter and steroid concentrations as covariates. IGFBP-2 mRNA was correlated with both day and diameter (r = -.713 and -.705, respectively, n = 24) and neither estrogen (E2) nor progesterone (P4) contributed to the fit. While IGF-I mRNA expression was correlated to both day (r = .483) and diameter (r = .587), the strongest predictor was E2 concentration (r = .694, n = 27). In conclusion, the expression of IGF-I and IGFBP-2 mRNAs in the ovarian follicle are discordantly regulated during follicular growth and maturation. The observed changes in these parameters should result in increased bioavailable IGF-I. This supports a pivotal autocrine/paracrine role for these factors during follicle growth and development.

Follicular fluid

Progestin

10.1210/endo.133.5.7691589

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Citations (49)

Interactions of estradiol with luteinizing hormone and cyclic nucleotides

Biology of Reproduction (1980)

Johannes D. Veldhuis PATRICIA A. KLASE James M. Hammond

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Steroid hormones modulate prolactin binding by cultured porcine granulosa cells