Pharmacokinetics and metabolism of sulphamonomethoxine in rainbow trout (Oncorhynchus mykiss) and yellowtail (Seriola quinqueradiata) following bolus intravascular administration

ELSEVIER

Aquaculture 153 (1997) 1-8

Pharmacokinetics and metabolism of sulphamonomethoxine in rainbow trout ( Oncorhynchus mykiss) and yellowtail ( Seriola quinqueradiata) following bolus intravascular administration Kazuaki Uno a**, Takahiko Aoki b, Ryuji Ueno b, Iwao Maeda a aDepartment of Food Science, Konan Women’s College, Konan. Aichi 483, Japan b Faculty of Bioresources. Mie Uniuersity, Tsu, Mie 514. Japa.n

Accepted 2 January 1997

Abstract The present study examined the pharmacokinetics and metabolism of sulphamonomethoxine @MM) in rainbow trout (Oncorhynchus mykiss) and yellowtail (Ser-iolu quinquerudiutu) after intravascular administration (100 mg kg- ’ body weight). Rainbow trout and yellowtail were kept in tanks with running water at 15.0 + 0.3”C and running sea water at 21.3 f 0.2”C, respectively. Serum concentrations of SMM were determined using high performance liquid chromatography with direct injection. Serum concentrations of SMM in rainbow trout and yellowtail were best described by a two-compartment model. The calculated half-lives for the distribution phase and the elimination phase were 0.43 h and 30.9 h for rainbow trout, and 0.53 h and 5.8 h for yellowtail, respectively. The apparent volume of distribution (V,) was larger in rainbow trout (V, = 0.83 1 kg-‘) than in yellowtail (V, = 0.56 1 kg- ‘1. Total body clearance was calculated as 18.5 ml kg-’ hP ’ in rainbow trout and 66.7 ml kg-’ hh ’ in yellowtail. The behaviour of N4-acetyl metabolite, N4-acetylsuiphamonomethoxine (AcSMM), in rainbow trout and yellowtail could be explained well by a one-compartment model. The formation rate constant of the metabolite and the elimination half-lives were 0.0694 h-’ and 15.4 h for rainbow trout, and 0.1896 h - ’ and 8.1 h for yellowtail, respectively. Acetylation in rainbow trout and yellowtail was calculated to be 23% and 64%, respectively. The serum protein bindings in vivo of SMM and

* Corresponding author. Tel.: + 81-587-55-6165; fax: + 81-587-55-6167; e-mail: [email protected]. 00448486/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved. PII SOO44-8486(97)00012-4

K. Uno et al. /Aquaculture

2

153 (1997) 1-8

AcSMM were determined to be 6.4 + 2.3% and 9.5 + 3.6% for rainbow trout, and 5.8 + 1.7% and 6.3 + 2.3% for yellowtail, respectively. 0 1997 Elsevier Science B.V. Keywords: Sulphamonomethoxine; N4-acetyl metabolite; Pharmacokinetics; Oncorhynchus mykiss: Seriola quinqueradiata; Protein binding

1. Introduction Recently, the efficiency of the use of sulphonamide derivatives in fish has been evaluated by pharmacokinetic analysis. The pharmacokinetics of sulphadimethoxine have been studied in rainbow trout, Oncorhynchus mykiss (Kleinow et al., 1992), channel catfish, Zctulurus punctutus (Michel et al., 1990) and lobster, Homarus americunus (Barr-on et al., 1988). The pharmacokinetics of sulphadimidine have also been examined in rainbow trout (Van Ginneken et al., 1991) and carp, Cyprinus curpio (Grondel et al., 1986; Van Ginneken et al., 1991). Sulphamonomethoxine @MM) is one of the most widely used sulphonamide derivative for therapeutic and prophylactic purposes in Japanese fish farming, and this drug was established as one of the subjects of regulations for fish drug in conformity with the Pharmaceutical Law in Japan (Fisheries Agency of Japan, 1992). Our previous studies reported the pharmacokinetics of SMM in rainbow trout and yellowtail after oral administration (Uno et al., 1993, Ueno et al., 1994). The present study examined the bolus intravascular pharmacokinetics of SMM and its N4-acetyl metabolite, N4-acetylsulphamonomethoxine (AcSMM), in rainbow trout and yellowtail using high-performance liquid chromatography (HPLC). We also estimated the binding of SMM and AcSMM to serum proteins in the two fish species.

2. Materials

and method

2.1. Chemicals Sodium sulphamonomethoxine @MM) was obtained from Daiichi Pharmaceutical (Tokyo, Japan). N4-acetylsulphamonomethoxine (AcSMM) was synthesized according to the method described in Japanese Pharmacopoeia (1981). Unless otherwise indicated, chemicals used were of analytical or HPLC grade. 2.2. Fish Rainbow trout (Oncorhynchus mykiss) with a mean weight of 171 + 15 g was obtained from the Nyunomata Salmonid Culture Farm in Mie Prefecture, Japan. Yellowtail (Seriolu quinquerudiutu) weighing 638 &-68 g was obtained from the Owase Branch, Fisheries Research Institution in Mie Prefecture, Japan. Rainbow trout were kept in tanks with running water at 15.0 &-0.3”C. Yellowtail were kept in tanks with running filtered sea water (3 1%0, pH 8.3). The water temperature was 21.3 + 0.2”C. Fish

K. Uno et al./Aquaculture

153 (1997) 1-8

3

were fed ad libitum with commercial pellets before use, and were allowed to adapt to these conditions for 7 days before the experiment started. 2.3. Administration Fish were superficially anesthetized with ethyl m-aminobenzoate (Sigma, Chemical Co. Ltd., St. Louis, MO, USA; 0.1 g 1-r of fresh or sea water), and SMM was injected as a single bolus into the caudal vein at a dose of 100 mg kg-’ of body weight. The position of the needle in the caudal vein was continned by aspirating blood into the syringe prior to the injection. If the needle had translocated during the injection, the fish was excluded and replaced. The substance for intravascular administration was dissolved in isotonic sterile phosphate buffered saline (PBS). The injection volume was 1.0 ml kg-’ body weight for rainbow trout and 0.5 ml kg-’ body weight for yellowtail. Four fish were sampled at each sampling time. 2.4. Blood sampling At each sampling, fish were killed by a blow to the head, and blood was sampled from the caudal vein, collected in Serum Separatory Tubes@ (Sumitomo Bakelite Co., Tokyo, Japan). The serum was obtained by centrifugation and kept frozen at -80°C until analysis. 2.5. Assay procedure SMM and AcSMM in serum were determined simultaneously by high performance liquid chromatography (HPLC) (Uno and Maeda, 1995). The HPLC system consisted of a Jasco PU-980 pump, UV-970 variable-wavelength absorbance detector (Japan Spectroscopic, Tokyo, Japan), a Rheodyne 7125 injector (Rheodyne, Cotati, CA, USA) with a 20 pl loop and a Chromatopac C-R6A integrator (Shimadzu Seisakusho, Kyoto, Japan). The analytical column was a HISEP’” shielded hydrophobic phase column, 15 cm X 4.6 mm ID, 5 pm particle size (Supelco, Bellefonte, PA, USA), protected with a guard column, 2 cm X 4.6 mm ID, packed with the same material. The mobile phase consisted of 0.05 M citric acid-O.2 M disodium hydrogenphosphate-acetonitrile (70:15:15, v/v). The pH was not adjusted. The flow rate was 1.0 ml min-‘, and the UV detector was set at 265 nm and 0.02 AUFS. The system was operated at room temperature. Serum samples were filtered through 0.45-pm disposable syringe filter units equipped with cellulose acetate membrane (Advantec, Tokyo, Japan). A 20-pl portion of the filtrate was directly injected into the chromatograph under the conditions described above. The recoveries of SMM and AcSMM from serum were 96.6% and 93.9% for rainbow trout, and 98.0% and 95.0% for yellowtail, respectively. The lowest measurable SMM and AcSMM concentrations were 0.04 and 0.1 mg ml-‘, respectively, for both fish serum. 2.6. Pharmacokinetic

analyses

All processes were assumed to follow first-order kinetics. The most common method of pharmacokinetic evaluation is to assume that the drug concentration-time data can be

K. Uno et al./Aquaculture

4

153 (1997) 1-8

described by one of several compartment models and to fit the data to an equation consistent with the assumed model using nonlinear least squares regression. In our study, pharmacokinetic analysis for the serum levels of SMM was performed using one-, two- and three-compartment models using the nonlinear least squares program MULTI (Yamaoka et al., 1981) according to the following C,=A*exp(-Ke-t) C,=A.exp(-a.t)

+B.exp(-p.t)

C,=A.exp(-cueb)

+Beexp(-p.t)

and +C-exp(-y-t)

where C, is the serum concentration, r is the time, (Y, p and y are values related to the slopes of distribution and elimination phases, and A, B and C are the zero-time serum concentrations. Selection of models was judged by Akaike’s information criterion (Yamaoka et al., 1978). Pharmacokinetic analysis for the serum levels of AcSMM was performed assuming a one-compartment open model for metabolites (Balant and McAinsh, 1980) C,=A[exp(-K,;t)-exp(-K;t)] where C, is the concentration of the metabolite, K,, is the elimination rate constant of the metabolite and K, is the formation rate constant of the metabolite. The area under the concentration-time curve (AUC) was calculated using the trapezoid rule, including the terminal portion. Calculations were performed by personal computer according to Yamaoka and Tanigawara (1983). 2.7. Acetylation Acetylation

in serum following

Acetylation

SMM administration

(%) = AUC,,s,M/(AUCs,,

was calculated

from

+ AUC,,,,,)

2.8. Binding of SMM and AcSMM to serum proteins The binding of SMM and AcSMM to serum proteins was determined by ultrafiltration using a Molcut II LGC (Nihon Millipore Ltd., Tokyo, Japan) with a 10000 nominal molecular weight cut-off limit. The total drug concentration and free drug fraction, ultrafiltrates of serum samples, were determined by HPLC as described above at each sampling time point. Bound drug was calculated as the difference between total and free components. The drug bound to the filter was determined by ultrafiltering 2 p,g ml-’ of SMM and of AcSMM in isotonic phosphate buffered saline (PBS), and comparing the drug level in the filtrates and the unfiltered sample. The recovery of SMM and AcSMM in the ultrafiltration procedure was 99.2% and 98.2%, respectively.

K. Uno et al./Aquaculture

153 (1997) I-8

3. Results Fig. 1 shows serum concentrations of SMM and AcSMM in rainbow trout and yellowtail after intravascular administration. Serum concentrations of SMM in rainbow trout and yellowtail were best described by a two-compartment model. The following equations were obtained to describe the time course of serum levels in the two fish species. Rainbow trout: C, = 219. exp( - 1.611 . t) + 123 . exp( - 0.0224.

t)

Yellowtail:

Pharmacokinetic in Table 1.

parameters

for SMM calculated

from these model equations

Rainbow

are given

trout

” E \ F

0

24

72

48

96

TZO

Yellowtail

0

12

24

Time after administration

36

48

(h)

Fig. 1. Serum concentration of sulphamonomethoxine (0) and N4-acetylsulphamonomethoxine rainbow trout and yellowtail after intravascular administration at a dose of 100 mg kg- ’ . Symbols mean and standard deviations for four fish.

(A ) in indicate the

6

K. Uno et al./Aquaculture

Table 1 Pharmacokinetic yellowtail

values

for sulphamonomethoxine

Parameter Water temperature Weight (g> Dose (mg kg-’ )

CC)

c, f&g ml-‘> A&g ml-‘) B (I-18 ml-‘) (Y (h-‘) p (h-l) T ,,zo (h) T,/,p

(h)

K,,

(h-‘1

K,,

(h-‘)

K,, (h-l) AUC(tqg.h&‘) Cl, (ml kg-’ V, (1 kg-‘) v, (I kg-‘)

h-r)

153 (1997) l-8

after intravascular

administration

to rainbow

Rainbow trout

Yellowtail

15.0*0.3 171+15 loo 342 219 123 1.6 0.02 0.4 30.9 0.0608 0.979 0.593 5398 18.5 0.8 0.3

21.3kO.2 638 f 68 100 371 211 160 1.3 0.01 0.5 5.8 0.2472 0.553 0.635 1500 66.7 0.5 0.3

trout and

C,, serum drug conctration at time 0. A, B, zero-time serum drug concentration intercepts of biphasic intravascular disposition curve. The coefficient B is baaed on the terminal exponential phase. (Y, /?, values related to the slopes of distribution and terminal phases, respectively, of biexponential drug disposition curve. T 1/2ol, T,,,p, distribution half-life and elimination half-life, respectively, of the drug. K,,, first-order rate constant for disappearance of drug from the central compartment. K,, , first-order rate constants for drug distribution between the central and peripheral compartments. K123 AUC, area under the concentration-time curve from zero to infinity. CI,, total body clearance. V,, apparent volume of distribution. V,, apparent volume of the central compartment.

Serum concentrations following equations. Rainbow trout:

of AcSMM

in the two species

C,,, = 192( exp( - 0.0449 . t) - exp( - 0.0694.

could

be described

by the

t))

Yellowtail: C,,, = 412(exp(

-0.0848.

t) - exp( -0.1896

+t))

Thus, the behaviour of N4-acetyl metabolite in rainbow trout and yellowtail could be explained well by a one-compartment model. The formation rate constant of the metabolite (K,) and the elimination half-lives were 0.0694 h- ’ and 15.4 h for rainbow trout, and 0.1896 h-’ and 8.1 h for yellowtail, respectively. The area under the concentration-time curve for metabolite (AUC,,,,,) and acetylation were presented in Table 2. A significant difference in the acetylation was revealed between rainbow trout and yellowtail.

K. Uno et al. /Aquaculture Table 2 Area under the concentration-time rainbow trout and yellowtail Fish

Rainbow trout Yellowtail Acetylation

153 (1997) l-8

curve of N4-acetylsulphamonomethoxine

I

(AUC,,,,,)

of

Acetylation

AUC ACSMM (p,g.h ml-‘)

(o/o)

1652 2137

23.4 64.6

(%) = AUCAcSMM /(AUCs,,

and acetylation

+ AUC,,,,,).

The serum protein bindings in vivo of SMM and AcSMM were determined to be 6.4 f 2.3% and 9.5 + 3.6% for rainbow trout, and 5.8 f 1.7% and 6.3 k 2.3% for yellowtail, respectively. Protein bindings were constant over the concentration range tested at each sampling time point.

4. Discussion In lobster (Barron et al., 1988), channel catfish (Michel et al., 1990) and rainbow trout (Kleinow et al., 1992), the pharmacokinetics of sulphadimethoxine were described by a two-compartment model. In common carp (Cyprinus carpio) the pharmacokinetics of sulphadimidine was analysed by a two-compartment model (Grondel et al., 1986; Van Ginneken et al., 1991). When evaluated by a two compartment model the apparent volume of the central compartment (V,) and distribution half-life (T,,2n) indicated that SMM was rapidly distributed to tissues outside the blood both in rainbow trout (v, = 0.29 1 kg-‘; Tl,2a = 0.43 h) and in yellowtail (V, = 0.27 1 kg-‘; T,,2a = 0.53 h). In comparison, Kleinow et al. (1992) determined V, = 0.15 1 kg-’ for sulphadimethoxine in rainbow trout. The apparent volume of distribution (V,) was larger in rainbow trout (V, =0.83 1 kg-‘) than in yellowtail (V, = 0.56 1 kg-‘). A large distribution volume gives an indication of the extent of distribution. Michel et al. (1990) and Van Ginneken et al. (1991) estimated V, = 0.40 1 kg-’ for sulphadimethoxine in catfish and V, = 1.15 1 kg-’ for sulphadimidine in carp, respectively. Total body clearance (CZ,> is an important parameter used to characterise drug disposition. Cl, was calculated to be 18.5 ml kg-’ h-’ in rainbow trout and 66.7 ml kg-’ h- ’ in yellowtail in the present study. The shorter elimination half-life (Tl,2p) in yellowtail is a consequence of a Cl, which is 3.6 times higher than in rainbow trout. Acetylation is a widely distributed reaction in mammalians, and the conjugation is catalysed by the enzyme N-acetyltransferase. The N4-acetyl metabolite has lost the antibacterial action, and it is less water-soluble than the parent drug, potentially leading to crystalluria, a contributing factor to renal damage (Caldwell, 1980). Our results show that the behaviour of N4-acetylsulphamonomethoxine (AcSMM) in rainbow trout and yellowtail could be explained well by a one-compartment model. The formation rate constant of the metabolite (K,) and the percentage of acetylation in yellowtail were almost three times larger than in rainbow trout. This indicates that yellowtail has a better ability to acetylate the parent drug than rainbow trout. These differences in acetylation

8

K. Uno et al./Aqwculrure

153 (1997)

1-8

may be due to differences in N-acetyltransferase activity between two fish species. Further investigations will be needed to elcidate these points. The protein binding of a drug can influence the concentration of active drug in the blood and its distribution into the tissues. In rainbow trout and yellowtail the protein bindings of SMM and AcSMM were very low. In contrast, Shimoda et al. (1983) reported that the protein binding of SMM was 60-65% in pigs.

References Balant, L.P. and McAinsh, J., 1980. Use of metabolite data in the evaluation of pharmacokinetics and drug action. In: P.J. Jenner and B. Testa (Editors), Concepts in Drug Metabolism, Part A. Marcel Dekker, New York, pp. 311-371. Barron, M.G., Gedutis, C. and James, O.M., 1988. Pharmacokinetics of sulphadimethoxine in the lobster, Homarus americanus, following intrapericardial administration. Xenobiotica, 18: 269-276. Caldwell, J., 1980. Conjugation reactions. In: P.J. Jenner and B. Testa (Editors), Concepts in Drug Metabolism, Part A. Marcel Dekker, New York, pp. 21 l-250. Fisheries Agency of Japan, 1992. A guide to approved chemicals in fish production and fishery resource management. Fisheries Agency of Japan. (In Japanese.) Grondel, J.L., Nouws, J.F.M. and Haenen, O.L.M., 1986. Fish and antibiotics: Pharmacokinetics of sulphadimidine in carp (Cyprinus carpio). Vet. Immunol. Immunopathol., 12: 281-286. Kleinow, K.M., Beilfuss, W.L., Jarboe, H.H., Droy, B.F. and Lech, J.J., 1992. Pharmacokinetics, bioavailability, distribution, and metabolism of sulphadimethoxine in the rainbow trout (Oncorhynchus mykiss). Can. J. Fish. Aquat. Sci., 49: 1070-1077. Michel, C.M.F., Squibb, K.S. and O’Connor, J.M., 1990. Pharmacokinetics of sulphadimethoxine in channel catfish ( Ic~ulurus puncfatus). Xenobiotica, 20: 1299- 1309. Shimoda, M., Tsuboi, T., Kokue, E. and Hayama, T., 1983. Dose-dependent pharmacokinetics of intravenous sulphamonomethoxine in pigs. Jpn. J. Pharmacol., 33: 903-905. Ueno, R., Uno, K. and Aoki, T., 1994. Pharmacokinetics of sulphamonomethoxine in cultured yellowtail after oral administration. Food Res. Int., 27: 33-37. Uno, K. and Macda, I., 1995. Simultaneous determination of sulphamonomethoxine and its N4-acetyl metabolite in blood serum by high-performance liquid chromatography with direct injection. J. Chromatogr. B, 663: 177-180. Uno, K., Aoki, T. and Ueno, R., 1993. Pharmacokinetics of sulphamonomethoxine and sulphadimethoxine following oral administration to cultured rainbow trout (Oncorhynchus my/&s). Aquaculture, 115: 209219. Van Ginneken, V.J.Th., Nouws, J.F.M., Grondel, J.L., Driessens, F. and Degen, M., 1991. Pharmacokinetics of sulphadimidine in carp (Cyprinus corpio L.) and rainbow trout (Salmo gairdneri Richardson) acclimated at two different temperature levels, Vet. Q., 13: 88-96. Yamaoka, K. and Tanigawara, Y., 1983. Statistical moments. In: Pharmacokinetics using Personal Computer. Nankoh-doh Press, Tokyo, pp. 113-139. (In Japanese.) Yamaoka, K., Nakagawa, T. and Uno, T., 1978. Application of Akaike’s information criterion (AIC) in the evaluation of linear pharmacokinetic equations. J. Pharmacokinet. Biopharm., 6: 165-175. Yamaoka, K., Tanigawara, Y., Nakagawa, T. and Uno, T., 1981. A pharmacokinetic analysis program (MULTI) for microcomputer. J. Pharmacol. Dyn., 4: 879-885.