Absorption and plasma kinetics of collagen tripeptide after peroral or intraperitoneal administration in rats

Abbreviations: ACN, acetonitrile; AUC, area under the curve; BBM, brush border membrane; C_max, maximum concentration; CTP, collagen tripeptide; i.p., intraperitoneal; LOD, limit of detection; LOQ, limit of quantification; MRM, multiple reaction monitoring; p.o., peroral; TCA, trichloroacetic acid; TFA, trifluoroacetic acid; T_max, maximum concentration time.

Figures & data

Fig. 1. Plasma levels of tripeptides and dipeptides after proral or intraperitoneal administration of CTP.

Notes: (A) Gly-Pro-Hyp, (B) Gly-Pro-Ala, (C) Gly-Ala-Hyp, (D) Pro-Hyp, (E) Gly-Pro, (F) Pro-Ala, (G) Ala-Hyp, and (H) Hyp-Gly. Values presented as the mean ± standard error, n = 5 subjects. Symbols: p.o.(◆), i.p.(□).

Table 1. AUC, C_max, and T_max of tripeptides and dipeptides in plasma after peoral administration of CTP.

	Tmax (min)		Cmax (nmol/mL)			AUC0–240 min
	p.o.	i.p.	p.o.	i.p.		p.o.	i.p.
Gly-Pro-Hyp	30.00 ± 0.00	16.67 ± 11.55	134.61 ± 38.37	133.25 ± 9.05		164.81 ± 41.94	129.81 ± 19.65
Gly-Pro-Ala	80.00 ± 34.64	40.00 ± 17.32	0.13 ± 0.02	0.12 ± 0.00		0.21 ± 0.02	0.18 ± 0.02
Gly-Ala-Hyp	100.00 ± 34.64	40.00 ± 17.32	0.05 ± 0.01	0.04 ± 0.00		0.07 ± 0.01	0.07 ± 0.01
Pro-Hyp	30.00 ± 0.00	30.00 ± 0.00	207.96 ± 35.57	202.85 ± 20.91		289.21 ± 30.14	255.20 ± 37.60
Gｌy-Pro	30.00 ± 0.00	10.00 ± 0.00^*	17.42 ± 2.17	20.74 ± 2.34		21.55 ± 0.92	19.83 ± 2.46
Pro-Ala	10.00 ± 0.00	10.00 ± 0.00	0.92 ± 0.26	0.90 ± 0.23		0.78 ± 0.09	0.51 ± 0.19
Ala-Hyp	23.33 ± 11.55	10.00 ± 0.00	2.41 ± 0.75	3.28 ± 0.99		1.96 ± 0.38	1.87 ± 0.40
Hyp-Gly	30.00 ± 0.00	16.67 ± 11.55	0.08 ± 0.00	0.08 ± 0.00		0.14 ± 0.00	0.11 ± 0.01

^* p < 0.05 compared with perorally administered Tmax of Gly-Pro.

Fig. 2. Whole-body autoradiographs 24hr after a single oral administration of Gly-[³H]Pro-Hyp to a fasting male rat.

Notes: Autradiographs of orally administrated Gly-[³H]Pro-Hyp to rat. The dose was 0.35 mmol/kg (74 MBq/kg).