title: Increased papillae growth and enhanced short-chain fatty acid absorption in the rumen of goats are associated with transient increases in cyclin D1 expression after ruminal butyrate infusion.
abstract: We tested the hypothesis that the proliferative effects of intraruminal butyrate infusions on the ruminal epithelium are linked to upregulation in cyclin D1 (CCND1), the cyclin-dependent kinase 4 (CDK4), and their possible association with enhanced absorption of short-chain fatty acids (SCFA). Goats (n=23) in 2 experiments (Exp.) were fed 200 g/d concentrate and hay ad libitum. In Exp. 1, goats received an intraruminal infusion of sodium butyrate at 0.3 (group B, n=8) or 0 (group C, n=7) g/kg of body weight (BW) per day before morning feeding for 28 d and were slaughtered 8 h after the butyrate infusion. In Exp. 2, goats (n=8) received butyrate infusion and feeding as in Exp. 1. On d 28, epithelial samples were biopsied from the antrium ruminis at 0, 3, and 7 h after the last butyrate infusion. In Exp. 1, the ruminal molar proportional concentration of butyrate increased in group B by about 110% after butyrate infusion and remained elevated for 1.5 h; thereafter, it gradually returned to the baseline (preinfusion) level. In group C, the molar proportional concentration of butyrate was unchanged over the time points. The length and width of papillae increased in B compared with C; this was associated with increased numbers of cells and cell layers in the epithelial strata and an increase in the surface area of 82%. The mRNA expression of CCND1 increased transiently at 3 h but returned to the preinfusion level at 7 h following butyrate infusion in Exp. 2. However, it did not differ between B and C in Exp. 1, in which the ruminal epithelium was sampled at 8 h after butyrate infusion. The mRNA expression of the monocarboxylate transporter MCT4, but not MCT1, was stably upregulated in B compared with C. The estimated absorption rate of total SCFA (%/h) increased in B compared with C. We conclude that transient increases in cyclin D1 transcription contribute to butyrate-induced papillae growth and subsequently to the increased absorption of SCFA in the ruminal epithelium of goats.
authors.affiliation: Laboratory of Animal Physiology and Biochemistry, Nanjing Agriculture University, 210095 Nanjing, China.
authors.forename: Moolchand
authors.initials: M
authors.lastname: Malhi
authors.forename: Hongbing
authors.initials: H
authors.lastname: Gui
authors.forename: Lei
authors.initials: L
authors.lastname: Yao
authors.forename: Jörg R
authors.initials: JR
authors.lastname: Aschenbach
authors.forename: Gotthold
authors.initials: G
authors.lastname: Gäbel
authors.forename: Zanming
authors.initials: Z
authors.lastname: Shen
mesh_terms: D000818:Animals; D019938:Cyclin D1; D004032:Diet / Q000662:veterinary; D005232:Fatty Acids, Volatile / Q000378:metabolism; D006041:Goats / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012417:Rumen / Q000378:metabolism
chemical_list: D005232:Fatty Acids, Volatile; D012333:RNA, Messenger; D019938:Cyclin D1
keywords: butyrate; cyclin D1 and monocarboxylate transporters; goat; rumen papillae growth and short-chain fatty acid absorption