Pharmacokinetics of amoxicillin trihydrate in Thai swamp buffaloes (Bubalus bubalis): a pilot study.

This study aimed to investigate the pharmacokinetic characteristics of amoxicillin (AMX) in Thai swamp buffaloes, Bubalus bubalis, following single intramuscular administration at two dosages of 10 and 20 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 48 h. The plasma concentrations of AMX were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The concentrations of AMX in the plasma were determined up to 24 h after i.m. administration at both dosages. The Cmax values of AMX were 3.39 ± 0.18 µg/mL and 6.16 ± 0.18 µg/mL at doses of 10 and 20 mg/kg, respectively. The AUClast values increased in a dose-dependent fashion. The half-life values were 5.56 ± 0.40 h and 4.37 ± 0.23 h at doses of 10 and 20 mg/kg b.w, respectively. Based on the pharmacokinetic data and PK-PD index (T > MIC), i.m. administration of AMX at a dose of 20 mg/kg b.w might be appropriate for the treatment of susceptible Mannheimia haemolytica infection in Thai swamp buffaloes.

Disposition of a long-acting oxytetracycline formulation in Thai swamp buffaloes (Bubalus bubalis).

The present study aimed to characterize the pharmacokinetic profile of oxytetracycline long-acting formulation (OTC-LA) in Thai swamp buffaloes, Bubalus bubalis, following single intramuscular administration at two dosages of 20 and 30 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 504 h. The plasma concentrations of OTC were measured by high-performance liquid chromatography (HPLC). The concentrations of OTC in the plasma were determined up to 264 h and 432 h after i.m. administration at doses of 20 and 30 mg/kg b.w., respectively. The Cmax values of OTC were 12.11 ± 1.87 µg/mL and 12.27 ± 1.92 µg/mL at doses of 20 and 30 mg/kg, respectively. The AUClast values increased in a dose-dependent fashion. The half-life values were 52.00 ± 14.26 h and 66.80 ± 10.91 h at doses of 20 and 30 mg/kg b.w, respectively. Based on the pharmacokinetic data and PK-PD index (T > MIC), i.m. administration of OTC at a dose of 30 mg/kg b.w once per week might be appropriate for the treatment of susceptible bacterial infection in Thai swamp buffaloes.

Role of cell death ligand and receptor system on regulation of follicular atresia in pig ovaries.

Several hundred thousand primordial follicles are present in the mammalian ovary, however, only a limited number develop to the pre-ovulatory stage, and then finally ovulate. The others, more than 99%, will be eliminated through a degenerative process called 'atresia'. The endocrinological regulatory mechanisms involved in follicular development and atresia have been characterized to a large extent, but the precise temporal and molecular mechanisms involved in the regulation of these events have remained unknown. From many recent studies, it is suggested that the apoptosis in ovarian granulosa cells plays a crucial role in follicular atresia. Notably, death ligand-receptor interaction and subsequent intracellular signalling have been demonstrated to be the key mechanisms regulating granulosa cell apoptosis. In this review, we provide an overview of granulosa cell apoptosis regulated by death ligand-receptor signalling. The roles of death ligands and receptors [Fas ligand (FasL)-Fas, tumour necrosis factor (TNF)alpha-TNF receptor (TNFR), and TNFalpha-related apoptosis-inducing ligand (TRAIL)-TRAIL receptor (TRAILR)] and intracellular death-signal mediators [Fas-associated death domain protein (FADD), TNF receptor 1-associated death domain protein (TRADD), caspases, apoptotic protease-activating factor 1 (Apaf1), TNFR-associated factor 2 (TRAF2), and cellular FLICE-like inhibitory protein (cFLIP), etc.] in granulosa cells will be discussed.