Table 1.
Ingredients and chemical compositions of concentrate and total mixed ration.
Fig 1.
Dipeptidyl peptidase-4 (DPP4) activity assessed in vitro.
Potassium EDTA plasma samples of three healthy dairy cows were incubated with different concentrations of BI 14332 (0, 1, 3, 10, 30 and 100 nM; 469 g/mol). The concentration of BI 14332 was significant (P = 0.006). a, b, c: Different letters indicate significant differences between dosages (P < 0.05, Tukey test).
Fig 2.
Inhibition of plasma and liver dipeptidyl peptidase-4 (DPP4) activities after injection of BI 14332.
BI 14332 was administered in a single dose of 3 [square], 1 [triangle] and 0.3 [circle] mg/kg body weight in dairy cows (n = 2/group). Plasma samples (V. jugularis) were taken 24 h before and immediately before (time zero “0”) injection, as well as 0.25, 0.5, 1, 2, 4, 6, 12, 24 and 48 h post injection (upper shape). Liver was biopsied 24 h before injection, as well as 4, 24 and 48 h thereafter (lower shape).
Table 2.
Pharmacokinetic parameters of BI 14332 und Dipeptidy peptidase-4 (DPP4) in plasma and liver of six healthy German Holstein cows treated with different dosages of BI 14332 [3, 1 and 0.3 mg/kg body weight (BW); n = 2/dosage group]a.
Fig 3.
Inhibition of dipeptidyl peptidase-4 (DPP4) activity in plasma and liver after injection of BI 14332.
BI 14332 was administered in a single dose of 3, 1 and 0.3 mg/kg body weight (BW) in dairy cows (n = 2/group). Plasma samples were taken 0.25, 0.5, 1, 2, 4, 6, 12, 24 and 48 h after the injection (V. jugularis; 3 mg/kg BW [□]; 1 mg/kg BW [Δ]; 0.3 mg/kg BW [○]). Liver samples were obtained by biopsy 4, 24 and 48 h after the injection (3 mg/kg BW [square]; 1 mg/kg BW [triangle]; 0.3 mg/kg BW [circle]). BI 14332 (x-axis) was shown to have a strong negative impact on DPP4 activity (y-axes), well approximated by a power function (represented as quasi linear model via log-log transformation) in liver: y = 7.72x-0.589 (r2 = 0.72) and plasma: y = 935.31x-0.081 (r2 = 0.76).
Fig 4.
Concentrations of non-esterified fatty acids (NEFA), glucose and insulin in serum, and insulin sensitivity (RQUICKI) in cows with subclinical ketosis.
With the first occurrence of serum β-hydroxybutyrate concentrations ≥ 1.2 mM, cows were treated with BI 14332 [(—) n = 6] or stayed untreated as control [(···) n = 6]. Within the BI 14332 treatment group subclinical ketosis was diagnosed on day +7 (5 cows) and on day +10 (1 cows), relative to calving. Dosage of BI 14332 was 0.3 mg/kg body weight, applied i.v. once a day over a period of 7 days. The statistical analysis included group (BI 14332 treatment vs. control), experimental day (1st day post partum until 56th day post partum), and the interaction (P < 0.05, Tukey test). Experimental day differed significantly for all parameters. [NEFA (diamond), Glucose (triangle), Insulin (circle), RQUICKI (square)].
Table 3.
Effects of dipeptidyl peptidase-4 (DPP4) inhibition via BI 14332 to blood serum variables of clinical chemistry and insulin sensitivity of cows with subclinical ketosis (LSmeans ±SE).
Table 4.
Effects of dipeptidyl peptidase IV inhibition via BI 14332 to dry matter intake (DMI) and milk yield of cows with subclinical ketosis (LSmeans ± SE).
Table 5.
Effects of dipeptidyl peptidase-4 (DPP4) inhibition via BI 14332 to hematological variables and the proliferative capability of PBMC (LSmeans ± SE).
Table 6.
Effects of dipeptidyl peptidase IV (DPP4) inhibition via BI 14332 to relative numbers of CD4+ and CD8+ T-lymphocytes (LSmean ± SE).