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Biomedical subjects

K K Kane

Publications and source records attributed to K K Kane.

17 recordsLinked to original sources
PubMed2006

Influence of short-term fasting during the luteal phase of the estrous cycle on ovarian follicular development during the ensuing proestrus of ewes.

Short-term fasting of mature ewes during diestrus results in increased serum concentrations of progesterone and a delayed pre-ovulatory surge release of LH. To determine if these changes in reproductive hormones influence subsequent follicular development, mature ewes observed in estrus were assigned randomly to control (n=10) or fasted (n=15) groups. Control ewes had ad libitum access to feed, whereas fasted ewes were not fed from day 7 through 11 of their estrous cycle. Daily blood samples were collected from control and fasted ewes throughout the fasting period. Fasting increased (P<0.001) serum concentrations of progesterone (4.4 ng/mL versus 2.7 ng/mL [+/-0.3]). On day 12, all ewes were treated with 10mg of PGF(2alpha) and fasted ewes were returned to ad libitum feed. Ovaries were collected from ewes (n=5 each group) at 0 and 72 h following PGF(2alpha) in control and 0, 72 and 96 h in fasted ewes. Ovaries were weighed and small (< or =2mm), medium (3-4mm), and large (> or =5mm) follicles were enumerated. Total numbers of follicles were less (P<0.001) in fasted than fed ewes (14.6 versus 30.2 [+/-2.2]) at 0 h, but did not differ (P=0.9) when numbers of follicles were compared at similar times before the anticipated LH surge (i.e., at 72 h versus 96 h in control and fasted ewes, respectively). Within follicular size class, numbers of small and medium follicles were decreased (P=0.04) at 0 h in fasted ewes. Numbers of large follicles did not differ (P=1.0) between groups. Although numbers of small and medium ovarian follicles in fasted ewes recovered by 96 h to values comparable to fed ewes at 72 h following PGF(2alpha), serum concentrations of estradiol 17beta (P=0.08) and FSH (P=0.06) tended to be decreased in fasted ewes before the anticipated surge release of LH. Pituitary content of LH and FSH also tended to be lower (P< or =0.09) at 96 h in fasted ewes than at 72 h in control ewes, but did not differ (P> or =0.4) at hour 0 following PGF(2alpha). Hypothalamic and stalk median eminence contents of GnRH were not influenced (P> or =0.2) by fasting at any time period. Fasting during the luteal phase perturbs gonadotropin secretion and may influence fertility by causing a delay in ovarian follicle development.

Animals↗
PubMed2004

Effect of increasing levels of undegradable intake protein on metabolic and endocrine factors in estrous cycling beef heifers.

To determine the influence of three levels of undegradable intake protein (UIP) supplementation on metabolic and endocrine factors that influence reproduction, 23 yearling crossbred heifers (body condition score = 4.5 +/- 0.5; initial BW = 362 +/- 12 kg) were stratified by BW and assigned randomly to one of three supplements: 1) low UIP (1,135 g x heifer(-1) x d(-1); 30% CP, 115 g UIP, n = 7); 2) mid UIP (1,135 g x heifer(-1) x d(-1); 38% CP, 216 g UIP, n = 8); or 3) high UIP (1,135 g x heifer(-1) x d(-1); 46% CP, 321 g UIP, n = 8). Heifers were estrually synchronized before initiation of supplementation. Supplement was individually fed daily for 30 to 32 d, at which time heifers were slaughtered (d 12 to 14 of the estrous cycle) and tissues collected. Heifers were fed a basal diet of sudan grass hay (6.0% CP) ad libitum. On d 28 of supplementation (d 10 of the estrous cycle), no differences were observed (P > 0.10) in serum insulin or IGF-I among treatments. At slaughter (d 10 to 12 of the estrous cycle), treatments did not influence corpus luteum weight, cerebral spinal fluid leptin, or IGFBP; serum estradiol-17beta, progesterone, leptin, IGF-I, and IGFBP; or anterior pituitary content of IGFBP (P > 0.10). Follicular fluid IGFBP-2 and IGFBP-4 were greater in high-UIP heifers than low- or mid-UIP heifers on d 12 to 14 of the estrous cycle (P < 0.05). Basal serum LH concentrations and LH area under the curve (every 15 min for 240 min) did not differ (P > 0.10) following 28 d of supplementation (d 10 of the estrous cycle); however, basal serum FSH concentrations were greater (P = 0.06) in low- and mid- vs. high-UIP heifers (5.2 and 5.2 vs. 4.6 ng/mL, respectively), and FSH area under the curve was greater (P = 0.03) in low- vs. high-UIP heifers. At slaughter (d 12 to 14 of the estrous cycle), anterior pituitary LH and FSH content and steady-state mRNA encoding alpha, LHbeta, and GnRH receptor did not differ (P > 0.10) among treatments. However, FSHbeta mRNA was increased approximately twofold (P = 0.03) in mid vs. low UIP. In summary, low and mid levels of UIP supplements fed to estrous cycling beef heifers seemed to enhance pituitary expression and/or secretion of FSH relative to high levels of UIP. Moreover, high-UIP supplementation was associated with increased low-molecular-weight IGFBP compared with supplementation of low and mid levels of UIP. These data suggest that differing levels of UIP supplementation may alter pituitary and ovarian function, thereby influencing reproductive performance in beef heifers.

Animal Nutritional Physiological Phenomena↗
PubMed2003

Effect of neuropeptide Y on GnRH-induced LH release from bovine anterior pituitary cell cultures derived from heifers in a follicular, luteal or ovariectomized state.

Objectives were to determine if neuropeptide Y (NPY) had direct effects GnRH induced secretion of LH from the anterior pituitary gland, and if endogenous steroids modulated the effect of NPY. To accomplish these objectives, 15 Hereford heifers were assigned to one of three ovarian status groups: follicular, luteal, or ovariectomized. One animal from each of the three ovarian status groups was slaughtered on each of 5 days and anterior pituitary gland harvested. Anterior pituitary gland cells within ovarian status were equally distributed and randomly assigned to one of three cell culture treatments: no NPY or GnRH (control), 10 nM GnRH, or 100 nM NPY+10 nM GnRH. Anterior pituitary cell cultures were incubated with or without NPY for 4 h and further incubated for an additional 2 h with or without GnRH and supernatant collected for quantification of LH. Treatment of anterior pituitary cell cultures with GnRH or GnRH+NPY did not affect LH release in cultures obtained from follicular (S.E.=5%; P=0.58) or ovariectomized (S.E.=7%; P=0.22) heifers. Both GnRH and GnRH+NPY increased LH release from anterior pituitary cell cultures from heifers in the luteal phase (S.E.=14%; P < or = 0.05) compared to control cultures. Cultures from luteal phase heifers treated with GnRH did not differ from those treated with GnRH+NPY (P=0.34). These data provide evidence to suggest that effects of NPY on LH release may occur primarily at the level of the hypothalamus.

Animals↗
PubMed2002

Effects of varying levels of undegradable intake protein on endocrine and metabolic function of young post-partum beef cows.

Twelve Hereford x Angus heifers, 2.5 year, 492 +/- 17 kg (BCS = 5 +/- 0.5), were randomly assigned to one of three supplements, stratified by calving date and calf sex. Treatments consisted of a daily equivalent of: (1) low undegradable intake protein (UIP) (L: 908 g per cow per day; 36% CP, 108 g UIP), (2) middle UIP (M: 908 g per cow per day; 36% CP, 165 g UIP), and (3) high UIP (H: 908 g M + 243 g feather meal per cow per day; 46% CP, 335 g UIP). Cows were fed sudan grass hay (7.3% CP, as fed) daily at 2% BW (as fed). Supplement was individually fed twice weekly from Week 2 to Week 11 post-partum. Cow body weight (BW), backfat (BF) and rumpfat (RF) thicknesses decreased in all cows, (P < 0.05) yet did not differ among treatments (P > 0.10). There were no differences among treatments in calf BW (P > 0.10). Serum insulin, blood urea nitrogen (BUN), milk components and yield did not differ among treatments (P > 0.10). Area under the curve (AUC) for serum LH was greater (P = 0.07) in H versus L and M (809 versus 599 and 607 +/- 69 U, respectively). No differences were observed in FSH AUC or mean serum concentrations (P > 0.10). Uterine pH did not differ among treatments or between supplement versus non-supplement days (P > 0.10). Serum progesterone remained below I ng/ml for all cows indicating absence of return to estrus. Under the conditions of this study, BW, BF, RF, serum insulin, BUN, milk components, and yield, uterine pH and serum FSH were not affected by level of UIP. However, supplement containing high levels of UIP enhanced GnRH-induced LH release.

Animal Nutritional Physiological Phenomena↗
PubMedDate not supplied

Fibrinolysis--a review.

The function of fibrinolysis is to dissolve fibrin clots. The agent of fibrinolysis is plasmin, a glycoprotein with gram molecular weight (GMW) of 90,000. Under natural conditions, plasminogen is converted to plasmin by tissue plasminogen activator (TPA). Activation occurs on the fibrin surface, thus confining proteolytic activity to the appropriate site. Tissue plasminogen activator, produced by monoclonal methods, has recently been made available for limited therapeutic use. Currently streptokinase and urokinase are widely used therapeutically to activate plasminogen. These agents cause plasmin to be formed which is free in the circulation as well as bound to fibrin, resulting in proteolysis of circulating plasminogen and clotting factors. Fibrinolytic therapy has proven to be more beneficial than anticoagulation alone for deep vein thrombi and for pulmonary emboli. During therapy, laboratory studies demonstrate reduced concentrations of plasminogen, fibrinogen, and of alpha-2 plasmin inhibitor, and prolongation of activated partial thromboplastin time and thrombin time. Laboratory findings must be correlated with the clinical course. Demonstration of circulating plasmin-antiplasmin complex may be a useful indicator of active fibrinolysis.

Aminocaproic Acid↗