Radiosynthesis of highly labelled [3H]Ac-Ser-Asp-Lys-Pro: A natural regulator of hematopoietic system

Sotty, Dominique; Lenfant, Maryse; Sasaki, André; Schott, D.; Roy, Jean; Morgat, Jean‐Louis

doi:10.1007/978-94-011-3034-9_133

Cited by 3 publications

(4 citation statements)

References 2 publications

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“…The ability of ACE resistant analogues to inhibit the hydrolysis of NAcSDKP ( 1 ) was studied by preincubating each one of them at different concentrations (0.5, 5, or 50 μM) with rabbit lung angiotensine-converting enzyme before adding the radiolabeled NAcSD[ 3 H]KP diluted with some cold peptide (5 μM). The tritium label was located in the lysine side chain . The conditions used for incubation are those used in the stability study.…”

Section: Ace Inhibition In Vitro Assaysmentioning

confidence: 99%

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NAcSDKP Analogues Resistant to Angiotensin-Converting Enzyme

et al. 1997

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Two series of analogues of the tetrapeptide NAcSDKP, an inhibitor of hematopoietic stem cell proliferation, were prepared, and their enzymatic stability toward rabbit lung angiotensin-converting enzyme (ACE) was evaluated as well as their capacity to inhibit NAcSDKP hydrolysis by this enzyme. In the first series, each of the peptide bonds has been successively replaced by an aminomethylene bond. In the second one, the C-terminus of the peptide has been modified by decarboxylation or amidation. The results reported here indicate that all of these molecules but one have good stability toward the enzyme but none of the compounds is able to inhibit NAcSDKP hydrolysis by ACE.

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Section: Ace Inhibition In Vitro Assaysmentioning

confidence: 99%

“…The tritium label was located in the lysine side chain. 15 The conditions used for incubation are those used in the stability study. Two control experiments were carried out: the first one was a simple hydrolysis of NAcSD[ 3 H]KP and the second one was an hydrolysis of NAcSD[ 3 H]KP in the presence of captopril (1 µM).…”

Section: Ace Inhibition In Vitro Assaysmentioning

confidence: 99%

NAcSDKP Analogues Resistant to Angiotensin-Converting Enzyme

et al. 1997

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“…The tetrapeptide AcSDKP (purity >95%) was generously supplied by IPSEN-Biotech (Paris, France). The radiolabeled AcSD[4,4′,5,5′-3 H]KP ([ 3 H]AcSDKP), specifically tritiated on the lysyl residue, was prepared, as previously described, with purity >99% determined by radiochromatography HPLC (Sotty et al, 1991). The specific radioactivity was about 90 Ci/mmol (3247 Gbq/mmol).…”

Section: Peptidementioning

confidence: 99%

Source, catabolism and role of the tetrapeptide N-Acetyl-Ser-Asp-Lys-Pro within the testis

Stéphan

Melaine

Ezan

et al. 2000

Journal of Cell Science

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The tetrapeptide N-Acetyl-Seryl-Aspartyl-Lysyl-Proline (AcSDKP) is a natural regulator of hematopoietic stem cell proliferation. The present study was aimed at investigating the presence and the role of AcSDKP in rat testis. Specific immunoreactivity was always observed in the interstitial tissue at all stages of testicular development and in elongated spermatids at 45 days of age and in adults. In accordance with the interstitial labeling, high AcSDKP levels were detected in Leydig cell and testicular macrophage culture media and cell extracts, as well as in the testicular interstitial fluid (TIF). Much lower concentrations were found in peritubular cells and Sertoli cells cultures, whereas very low concentrations were present in cultured spermatocytes and spermatids. In contrast to the slight degradation rate of AcSDKP observed in the spermatocyte and spermatid culture media, no catabolism of the peptide was seen in testicular somatic cell culture medium. Furthermore, the degradation rate of AcSDKP was much lower in TIF than in peripheral blood plasma. Despite the very strong evidence indicating that Leydig cells and testicular macrophages produce AcSDKP, the selective destruction of these cells did not result in any change in AcSDKP levels in TIF or in plasma. This suggests a compensatory mechanism ensuring constant levels of the peptide in TIF when interstitial cells are absent. Finally, in vitro, in the presence of AcSDKP, significantly more [(3)H]thymidine incorporation was found in A spermatogonia. In conclusion, this study establishes the presence of very high concentrations of AcSDKP in rat testis and demonstrates its Leydig cell and testicular macrophage origin. The presence of AcSDKP in the TIF and its stimulatory effect on thymidine incorporation in spermatogonia very strongly suggest its implication in the paracrine control of spermatogenesis.

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“…Solutions of 20 mg mL ¹1 and 2 mg mL ¹1 were prepared by reconstituting the lyophilized powder in physiological saline solution just before use. The radiolabelled [ 3 H]-AcSDKP, specifically tritiated on the lysyl residue, was prepared as previously described [23]; its specific radioactivity was about 87 Ci mmol ¹1 (3·29 TBq mmol ¹1 ). 5-Fluorouracil (1 g per 20 mL, Roche Laboratory) was diluted (100 mg mL ¹1 ) in physiological saline solution at the time of use.…”

Section: Reagentsmentioning

confidence: 99%