The aim of the study was to investigate the effects of feeding two fibre and two protein sources, differing in rate of fermentation and digestion, on motility and morphology of pig colon. Pigs of ...15.1
±
0.9
kg of BW were fed during 21
days with diets containing potato fibre (PF) or cellulose (CEL) in combination with potato protein concentrate (PPC) or casein (CAS). After slaughter, tissue samples of proximal (C25), middle (C50) and distal (C75) part of the colon were taken for analysis of
in vitro mechanical activity and of histological parameters. Spontaneous activity, responses to acetylcholine (ACh), electrical field stimulation (EFS), responses to short chain fatty acids (SCFA) and relaxation induced by single administration of isoproterenol were recorded. Crypt depth and myenteron thickness were measured. The amplitude of spontaneous contractions of colon segments was similar in all groups. In neither colon segment, responses to EFS, SCFA and relaxation induced by isoproterenol were not affected by the sources of fibre and protein. Response to ACh was significantly enhanced in C25 in pigs fed CAS as compared with PPC. The effects of type of dietary fibre and dietary protein on colon morphology differed between the segments and parameters under study. The effect of fibre was not found in C50. The effect of fibre type on colon morphology was of greater magnitude than that of protein but in some parameters interactive effects could be traced. The results suggest that effects of type of dietary fibre and protein on colonic morphology depend on the part of the colon. Fibre and protein sources do not affect motility in middle and distal parts of colon, but protein source affects muscular contractions in proximal colon, assayed
in vitro.
Two experiments were carried out using a balanced feed mixture composed of wheat, corn, soyabean meals, casein, and crystalline amino acids (AA) and supplemented with 0, 4, or 8% of apple pectin. The ...daily dietary allowance provided pigs with the same level of nutrients, apart from the pectin. One experiment was conducted on pigs (within 25 to 40 kg BW) with the post valve T-caecum (PVTC) cannula to determine AA digestibility and ileal digesta viscosity. In the second experiment, the N-balance was measured twice on male pigs at about 20 and 28 kg BW using 6 animals per diet and feed intake and body weight were measured twice during the 28 d. After 40 d of feeding the diets, the pigs were sacrificed and the small intestines were weighed and sampled. The added pectin decreased standardized ileal AA digestibility (on average up to 5% dig. units) and increased digesta viscosity from about 1 to 88 mPa s. The higher pectin level did not affect motility of the duodenum and mid-jejunum, measured as responses to electrical field stimulation and to acetylcholine. However, the response of the duodenum to electrical field stimulation was after feeding the diet with 4% pectin increased compared with other diets. Pectin supplementation did not alter the weight and the length of the small intestine, but induced changes in the intestinal morphology. Muscle layer width increased significantly in the duodenum, the mid-jejunum, and the ileum while villi length increased in the duodenum and ileum. The addition of pectin decreased N retention and increased the F/G ratio but did not affect significantly the ADG of the pigs.
Threonine (Thr) plays various roles in maintaining gut functions. The aim of the study was to investigate effects of dietary Thr on smooth muscle mechanical activity in the small intestine of growing ...pigs. Four cereal diets were used: T0 (unsupplemented, Thr-deficient), T1, T2, and T3 containing 6.5, 7.4, 8.4, and 9.3
g Thr per kg diet, respectively. Pigs of mean initial BW of 12.8
kg were fed diets for 19
days. Each group consisted of six animals. The animals were sacrificed at about 22.0
kg of BW and the longitudinal strips of the duodenum and the mid-jejunum were taken for in vitro measurement. Spontaneous activity, responses to electrical field stimulation (EFS; from 0.5 to 30
Hz), responses to acetylcholine (ACh; from 10
−
10
to 10
−
4
M), and relaxation induced by single administration of isoproterenol (10
−
5
M) were recorded. In the duodenum, the amplitude of spontaneous contractions was similar in all groups, while, in the mid-jejunum, the amplitude was significantly larger in group T3 than in other groups. In the duodenum, only responses to EFS were enhanced in group T1 in comparison to group T2. In the mid-jejunum, no differences in responses to EFS were found, but responses to low doses of ACh were enhanced in animals fed diet T3, in comparison with diets T1 and T2, and relaxation induced by isoproterenol was significantly more profound in group T2, as compared with groups T0 and T1. In conclusion, dietary Thr may affect motility of the small intestine. Most likely, Thr plays role in facilitation of contractile cholinergic pathways in the pig jejunum, while the effect in duodenum is equivocal and may involve other pathways.
The aim of the study was to investigate the effect of dietary protein level on contractility of the small intestine in young pigs. Animals (about 15 kg BW initially) were fed during 40 days with ...isoenergetic diets containing 16, 18, or 20% of crude protein. Higher protein levels in the diets as well as similar concentration of essential amino acids were attained by substitution of corn starch with wheat gluten and crystalline amino acids. At about 40 kg BW, the animals were sacrificed and the longitudinal strips of duodenum and mid-jejunum were taken for analysis of smooth muscle mechanical activity
in vitro. Spontaneous activity, responses to electrical field stimulation (EFS), and responses to acetylcholine (ACh) were recorded. Frequency and amplitude of spontaneous contractions were similar in all groups, both in the duodenum and the mid-jejunum. In the duodenum, responses to EFS and ACh were the same irrespective of the dietary protein level. Responses to EFS in the mid-jejunum were significantly enhanced in the animals receiving the diet with 20% protein; however, the response to ACh was not changed. The mechanism of neuronal response may involve primary afferent pathways “sensing” contents in the lumen of the intestine through enterochromaffin cells. The enteric neuronal pathways may also be activated by a higher level of free amino acid(s) or by dietary peptides and proteins.
Central and local (enteric) action of orexins Korczynski, W; Ceregrzyn, M; Matyjek, R ...
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society
57 Suppl 6
Journal Article
Peer reviewed
Orexin-A (OXA, hypocretin-1) and orexin-B (OXB, hypocretin-2) are peptides derived from the same 130 amino acid long precursor (prepro-orexin) that bind and activate two closely related orphan G ...protein-coupled receptors. Orexins and their receptors were first discovered in the rat brain, and soon after that in peripheral neural structures, including the vagal nerve and enteric nervous system, and in other structures involving the gastrointestinal tract diffuse neuroendocrine system, pancreas tissue, stomach and intestinal mucosa. Orexins and their receptors were also demonstrated in the testes, adrenals, kidneys, and placenta. This review is focused on central and enteric actions. Originally, orexins were considered to be neurotransmitters that centrally stimulate food intake in animals and humans, but it soon became evident that their action is broader due to activation of a large number of neuronal pathways involved in energy homeostasis, sleep-awake behavior, nociception reward seeking, food and drug addiction, as well as reproduction, cardiovascular and adrenal function. In the gastrointestinal tract, orexins have been found so far to affect gastrointestinal motility and gastric, intestinal and pancreatic secretions. The effects were observed following central (intraventricular) or local (intraluminal, intraarterial), but not peripheral (intravenous), administrations of orexins. Since the expression of orexins in the gastrointestinal tract is enhanced during fasting, and fasting reveals many of the orexin gastrointestinal effects, it seems probable that on the local level, orexins keep the gastrointestinal tract functions ready during fasting and play role in brain-gut axis control.
Orexin-A and -B (OXA, OXB) are peptides involved in many gastrointestinal (GI) functions, including motility. Orexins, their precursors and receptors are present in the GI tract. The expression of ...orexins increases in the hypothalamus and gastrointestinal tract in response to fasting. We have examined the effect of OXA and OXB on GI motility in vitro in fed and fasted rats. The intestinal segments were mounted in chambers filled with Krebs solution. Isotonic contractions were measured in response to acetylcholine (10(-5) M), electric field stimulation (EFS), and orexins (10(-9)-10(-7) M) alone or in the presence of orexin-1 type receptor antagonist, SB- 334867 (10(-5) M), tetrodotoxin (TTX) 10(-6) M, or atropine (10(-5) M). Orexins caused a dose-dependent increase of intestinal segment contractions with a more pronounced effect of OXB over OXA. Fasting did not influence orexin-induced responses. Incubation with SB-334867 led to a marked decrease in orexin-induced contractions in OXA-treated segments, while those of OXB were not affected. Atropine diminished contractions only in fasted animals, while TTX led to a decreased response to orexins in both groups. The results show that OXB is predominant in inducing gut motility response, that the effect of orexins is not fully dependent on cholinergic and Na(+) transmissions, and that involvement of other transmitters is possible.
A method of recording oviduct and uterine myoelectrical activity in gilts using implantable telemetry Wolinski, J. (Polish Academy of Sciences, Jablonna (Poland). Kielanowski Institute of Animal Physiology and Nutrition); Ziecik, A. (Polish Academy of Sciences, Olsztyn (Poland). Inst. of Animal Reproduction and Food Research, Div. of Food Science); Gajewski, Z. (Warsaw Agricultural University (Poland). Dept. of Animal Reproduction) ...
Journal of Animal and Feed Sciences,
01/2003, Volume:
12, Issue:
2
Journal Article
Peer reviewed
Open access
A method of telemetric recording of myoelectrical activity (EMG) in the female pig reproductive tract is described. In 10 gilts the telemetry implant was placed extraperitoneally between the ...abdominal muscle layers and connected with two or three bipolar silver electrodes sutured on different parts of the uterus and oviducts. The animals recovered from surgery quickly and without complications. The radio waves sent by the implant were collected and demodulated by a receiver and then recorded on a computer disk. Two-three hour recording sessions were performed every 2-3 days. The electrodes collected EMG signals free of artifacts for 5-6 weeks after surgery. Off-line analysis of myometry and oviduct EMG activities showed no major differences from the activities measured earlier by conventional wire methods. In conclusion, a commercially available telemetry system can be used for reproductive tract myoelectric activity studies in pigs
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