title: Nursing supports neonatal porcine testicular development.
abstract: The lactocrine hypothesis suggests a mechanism whereby milk-borne bioactive factors delivered to nursing offspring affect development of neonatal tissues. The objective of this study was to assess whether nursing affects testicular development in neonatal boars as reflected by: (1) Sertoli cell number and proliferation measured by GATA-4 expression and proliferating cell nuclear antigen immunostaining patterns; (2) Leydig cell development and steroidogenic activity as reflected by insulin-like factor 3 (INSL3), and P450 side chain cleavage (scc) enzyme expression; and (3) expression of estrogen receptor-alpha (ESR1), vascular endothelial growth factor (VEGF) A, and relaxin family peptide receptor (RXFP) 1. At birth, boars were randomly assigned (n = 6-7/group) to nurse ad libitum or to be pan fed porcine milk replacer for 48 h. Testes were collected from boars at birth, before nursing and from nursed and replacer-fed boars at 50 h on postnatal day (PND) 2. Sertoli cell proliferating cell nuclear antigen labeling index increased (P < 0.01) from birth to PND 2 in nursed, but not in replacer-fed boars. Sertoli cell number and testicular GATA-4 protein levels increased (P < 0.01) from PND 0 to PND 2 only in nursed boars. Neither age nor nursing affected testicular INSL3, P450scc, ESR1, or VEGFA levels. However, testicular relaxin family peptide receptor 1 (RXFP1) levels increased (P < 0.01) with age and were greater in replacer-fed boars on PND 2. Results suggest that nursing supports neonatal porcine testicular development and provide additional evidence for the importance of lactocrine signaling in pigs.
authors.affiliation: Department of Animal Sciences, Endocrinology and Animal Biosciences Program, Rutgers University, New Brunswick, NJ, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Rahman
authors.affiliation: Department of Animal Sciences, Endocrinology and Animal Biosciences Program, Rutgers University, New Brunswick, NJ, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Lovich
authors.affiliation: Department of Animal Sciences, Endocrinology and Animal Biosciences Program, Rutgers University, New Brunswick, NJ, USA.
authors.forename: C
authors.initials: C
authors.lastname: Lam
authors.affiliation: Department of Animal Sciences, Endocrinology and Animal Biosciences Program, Rutgers University, New Brunswick, NJ, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Camp
authors.affiliation: Department of Anatomy, Physiology and Pharmacology, Cellular and Molecular Biosciences Program, Auburn University, Auburn, AL, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Wiley
authors.affiliation: Department of Anatomy, Physiology and Pharmacology, Cellular and Molecular Biosciences Program, Auburn University, Auburn, AL, USA.
authors.forename: F F
authors.initials: FF
authors.lastname: Bartol
authors.affiliation: Department of Animal Sciences, Endocrinology and Animal Biosciences Program, Rutgers University, New Brunswick, NJ, USA. Electronic address: bagnell@aesop.rutgers.edu.
authors.forename: C A
authors.initials: CA
authors.lastname: Bagnell
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D049109:Cell Proliferation; D003577:Cytochrome P-450 Enzyme System; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D050991:GATA4 Transcription Factor / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D007328:Insulin / Q000235:genetics / Q000378:metabolism; D007985:Leydig Cells / Q000166:cytology / Q000378:metabolism; D008297:Male; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis; D013552:Swine / Q000254:growth & development*; D013737:Testis / Q000166:cytology / Q000254:growth & development*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D050991:GATA4 Transcription Factor; D007328:Insulin; C084797:Leydig insulin-like protein; D018809:Proliferating Cell Nuclear Antigen; D011506:Proteins; D043562:Receptors, G-Protein-Coupled; D013256:Steroids; D042461:Vascular Endothelial Growth Factor A; D003577:Cytochrome P-450 Enzyme System
keywords: Development; Lactocrine; Neonate; Sertoli and Leydig cells; Testis