Genetic Toxicology - Mammalian Cell Mutagenicity

Study Information
Study Attribute	Value
CEBS Accession Number:	002-02122-0008-0000-7
Chemical Name:	Erythromycin stearate
CASRN:	643-22-1
NTP Study Type:	Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID:	146253
Study Result:	Equivocal

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Table Instructions and Notes:
Studies are indicated to be "Nontoxic" when the observed reductions in relative total growth did not indicate that the maximum tolerated dose was achieved.

Nonactivation Trial: 1 Experiment Call: Equivocal
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	94	107	226	80	70
			78	101	158	68
			81	94	167	69
			77	98	150	65
Test Chemical	Erythromycin stearate	6.25	78	73	174	74	71
			86	78	201	78
			109	81	196	60
		12.5	75	76	210	94	84
			98	102	238	81
			94	67	220	78
		25	93	84	223	80	74
			98	76	189	64
			99	83	228	77
		50	83	55	216	87	87
			78	51	210	90
			82	53	204	83
		100	85	7	283	111	118*
			63	5	226	119
			77	6	287	124
		150	83#	4	360	144	155*
			79	3	444	189
			64	3	252	131
		200


Positive Control	Ethyl Methane Sulfonate	250	69	54	929	450	527*
			71	45	1205	566
			68#	42	1156	567

Nonactivation Trial: 2 Experiment Call: Equivocal
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	74	120	85	39	48
			96#	115	115	40
			61	88	106	58
			54	77	88	54
Test Chemical	Erythromycin stearate	25	64	76	77	40	35
			42#	56	42	33
			66#	82	62	31
		50	68	21	107	52	42
			76	26	96	42
			48	24	47	32
		75	55#	17	81	49	48
			58	21	70	40
			65	21	107	55
		100	69#	16	130	63	65
			61	17	116	63
			58	17	121	70
		125	51	16	122	79	74*
			63	16	133	71
			47	13	101	72
		150	55	16	101	61	59
			77	20	131	56
			49	16	85	58
Positive Control	Ethyl Methane Sulfonate	250	38	44	744	656	532*
			51	68	765	498
			61#	65	809	443

Nonactivation Trial: 3 Experiment Call: Equivocal
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	90	100	78	29	25
			93	100	53	19
			101	94	77	25
			116	107	93	27
Test Chemical	Erythromycin stearate	40	83	31	61	24	26
			59	23	49	28
			124r	39	110	30
		60	71	7	39	18	30
			68	11	71	35
			89	16	95	36
		80	60	5	54	30	41*
			65	6	67	34
			64	5	113	59
		100	57	3	75	44	49*
			50#	4	74	50
			56	4	90	54
Positive Control	Methyl Methane Sulfonate	5	82	53	618	250	197*
			58	47	293	169
			88	82	448	170

Non-Induced S9 Trial: 1 Experiment Call: Negative and Non-Toxic
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	99	101	104	35	31
			98#	92	68	23
			99#	115	88	30
			87	91	98	38
Test Chemical	Erythromycin stearate	62.5	72	76	93	43	37
			84	85	79	31
			70	77	78	37
		125	83	71	108	43	37
			94	77	96	34
			79#	80	78	33
		250	91	60	107	39	39
			93	72	100	36
			84#	66	107	42
		500	85	54	94	37	38
			127r	73	163	43
			84	54	101	40
		750	64	19	106	55	59*
			70	16	148	71
			75	22	113	50
		1000


Positive Control	3-Methylcholanthrene	3.5	122r	81	494	135	133*
			107	72	429	133
			132r	60	547	139

Induced S9 Trial: 1 Experiment Call: Negative and Non-Toxic
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	76	100	99	44	46
			74	89	104	47
			78	101	90	39
			74	111	123	55
Test Chemical	Erythromycin stearate	31.3	89	72	104	39	41
			67	73	86	43	41
		62.5	63	68	83	44	37
			90	77	81	30	37
		125	82	70	113	46	49
			79	67	121	51	49
		250	76	46	141	62	51
			81	71	115	47
			78	66	106	45
		750	75	37	101	45


		1000

		1500


Positive Control	3-Methylcholanthrene	2.5	82	76	376	153	153*

Induced S9 Trial: 2 Experiment Call: Inconclusive
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	75	72	221	99	102
			90	94	229	85
			87	101	301	115
			95	132	310	109
Test Chemical	Erythromycin stearate	31.3	47	64	237	169	166*
			58	66	263	152
			43#	44	229	178
		62.5	58	68	235	135	110
			73	72	220	101
			82	78	229	93
		125	75	81	224	99	120
			73	70	273	125
			59#	64	238	134
		250	104	67	415	133	142
			69	64	342	166
			68	47	260	127
		500	59	30	351	197	198*
			78	44	401	172
			58#	43	390	224
		750	42	8	416	329


		1000


Positive Control	3-Methylcholanthrene	2.5	67	30	710	356	334*
			76	67	707	311
			72	50	721	336

Induced S9 Trial: 3 Experiment Call: Negative and Non-Toxic
		Conc. ug/mL	Cloning Efficiency	Relative Total Growth	Mutant Colonies	Mutant Frequency	Avg Mutant Frequency
Vehicle Control	Ethanol	0	67	96	132	65	66
			75	117	145	65
			62	94	150	81
			84	93	135	54
Test Chemical	Erythromycin stearate	100	58	67	92	53	43
			69#	96	87	42
			80	95	80	33
		200	77	93	146	64	58
			87	119	94	36
			64	63	141	73
		400	40	34	167	139	75
			64	49	92	48
			83	59	94	38
		500	35	7	187	181	148*
			35	6	169	160
			72	19	223	103
		600	38	7	219	190	175*
			62	21	176	94
			33	5	239	240
		700	50	8	214	143	103*
			64	30	186	97
			73	74	148	67
		800


Positive Control	3-Methylcholanthrene	2.5	81	77	625	257	275*
			64	60	629	326
			67	76	488	242

Footnotes:
Asterisks(*) indicate significant responses.
r = rejected value due to quality control criteria
# = reduced sample size because of the loss of one culture dish due to contamination